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This module describes the commands used to configure and monitor the Open Shortest Path First (OSPF) routing protocol.
For detailed information about OSPF concepts, configuration tasks, and examples, see the Implementing OSPF on Cisco IOS XR Software module in the Cisco IOS XR Routing Configuration Guide for the Cisco XR 12000 Series Router .
To enter address family configuration mode for Open Shortest Path First (OSPF), use the address-family command in the appropriate mode. To disable address family configuration mode, use the no form of this command.
address-family ipv4 [unicast]
no address-family ipv4 [unicast]
ipv4 |
Specifies IP Version 4 (IPv4) address prefixes. |
unicast |
(Optional) Specifies unicast address prefixes. |
An address family is not specified.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
OSPF version 2 automatically provides routing services for IPv4 unicast topologies, so this command is redundant.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the OSPF router process with IPv4 unicast address prefixes:
RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# address-family ipv4 unicast
To configure staggering of OSPF adjacency during reload, process restart, and process clear, use the adjacency stagger command in router configuration mode. To turn off adjacency staggering, either use the disable keyword or use the no form of this command.
adjacency stagger { disable | initial-num-nbr max-num-nbr }
no adjacency stagger
disable |
Disables adjacency staggering. |
initial-num-nbr |
The initial number of simultaneous neighbors allowed to form adjacency to FULL in any area to bring up to FULL after a router reload, OSPF process restart, or OSPF process clear. Range is 1-65535. Default is 2. |
max-num-nbr |
The subsequent number of simultaneous neighbors allowed to form adjacency, per OSPF instance, after the initial set of OSPF neighbors have become FULL. Range is 1-65535. Default is 64. |
OSPF adjacency staggering is enabled.
Router configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Staggering of the OSPF adjacency during reload, process restart (without NSR or graceful-restart), and process clear reduces the overall adjacency convergence time.
Initially, allow 2 (configurable) neighbors to form adjacency to FULL per area. After the first adjacency reaches FULL, up to 64 (configurable) neighbors can form adjacency simultaneously for the OSPF instance (all areas). However, areas without any FULL adjacency is restricted by the initial area limit.
Note | Adjacency stagger and OSPF nonstop forwarding (NSF) are mutually exclusive. Adjacency stagger will not be activated if nsf is configured under router ospf configuration. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure adjacency stagger for a 2 neighbors initially and for a maximum of 3 neighbors:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# adjacency stagger 2 3
To configure an Open Shortest Path First (OSPF) area, use the area command in the appropriate mode. To terminate an OSPF area, use the no form of this command.
area area-id
no area area-id
area-id |
Identifier of an OSPF area. The area-id argument can be specified as either a decimal value or an IP address (dotted decimal) format. Range is 0 to 4294967295. |
No OSPF area is defined.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the area command to explicitly configure an area. Commands configured under the area configuration mode (such as the interface [OSPF] and authentication commands), are automatically bound to that area.
To modify or remove the area, the area-id argument format must be the same as the format used when creating the area. Otherwise, even if the actual 32-bit value matches, the area is not matched. For example, if you create an area with an area-id of 10 it would not match an area-id of 0.0.0.10.
Note | To remove the specified area from the router configuration, use the no area area-id command. The no area area-id command removes the area and all area options, such as authentication , default-cost , nssa , range , stub , virtual-link , and interface. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure area 0 and GigabitEthernet interface 0/2/0/0. GigabitEthernet interface 0/2/0/0 is bound to area 0 automatically.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/2/0/0
To enable plain text, Message Digest 5 (MD5) authentication, or null authentication for an Open Shortest Path First (OSPF) interface, use the authentication command in the appropriate mode. To remove such authentication, use the no form of this command.
authentication [ message-digest [ keychain keychain ] | null ]
no authentication
message-digest |
(Optional) Specifies that MD5 is used. |
keychain keychain |
(Optional) Specifies a keychain name. |
null |
(Optional) Specifies that no authentication is used. Useful for overriding password or MD5 authentication if configured for an area. |
If this command is not specified in interface configuration mode, then the interface adopts the authentication parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the authentication parameter specified for the process.
If this command is not specified at any level, then the interface does not use authentication.
If no keyword is specified, plain text authentication is used.
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area interface configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.5.0 |
The keychain keychain keyword and argument pair was added. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the authentication command to specify an authentication type for the interface, which overrides the authentication specified for the area to which this interface belongs. If this command is not included in the configuration file, the authentication configured in the area to which the interface belongs is assumed (as specified by the area authentication command).
The authentication type and password must be the same for all OSPF interfaces that are to communicate with each other through OSPF. If you specified plain text authentication, use the authentication-key command to specify the plain text password.
If you enable MD5 authentication with the message-digest keyword, you must configure a key with the message-digest-key interface command.
To manage the rollover of keys and enhance MD5 authentication for OSPF, you can configure a container of keys called a keychain with each key comprising the following attributes: generate/accept time, key identification, and authentication algorithm. The keychain management feature is always enabled.
Note | Changes to the system clock will impact the validity of the keys in the existing configuration. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set authentication for areas 0 and 1 of OSPF routing process 201. Authentication keys are also provided.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# router-id 10.1.1.1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# authentication RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# authentication-key mykey RP/0/0/CPU0:router(config-ospf-ar-if)# exit RP/0/0/CPU0:router(config-ospf)# area 1 RP/0/0/CPU0:router(config-ospf-ar)# authentication RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# authentication-key mykey1
The following example shows how to configure use of an authentication keychain:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# router-id 10.1.1.1 RP/0/0/CPU0:router(config-ospf)# authentication message-digest keychain mykeychain
Command |
Description |
---|---|
Assigns a password to be used by neighboring routers that are using the simple password authentication of OSPF. |
|
Specifies a key used with OSPF MD5 authentication. |
To assign a password to be used by neighboring routers that are using the Open Shortest Path First (OSPF) simple password authentication, use the authentication-key command in the appropriate mode. To remove a previously assigned OSPF password, use the no form of this command.
authentication-key [ clear | encrypted ] password
no authentication-key
clear |
(Optional) Specifies that the key be clear text. |
encrypted |
(Optional) Specifies that the key be encrypted using a two-way algorithm. |
password |
Any contiguous string up to 8 characters in length that can be entered from the keyboard. For example, mypswd2. |
If this command is not specified in interface configuration mode, then the interface adopts the OSPF password parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the OSPF password parameter specified for the process.
If this command is not specified at any level, then no password is specified.
Clear is the default if the clear or encrypted keyword is not specified.
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The password created by this command is inserted directly into the OSPF header when the Cisco IOS XR software originates routing protocol packets. A separate password can be assigned to each network on an individual interface basis. All neighboring routers on the same network must have the same password to be able to exchange OSPF information.
The authentication-key command must be used with the authentication command. If the authentication command is not configured, the password provided by the authentication-key command is ignored and no authentication is adopted by the OSPF interface.
Note | The authentication-key command cannot be used with the authentication command when the message-digest or null keyword is configured. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure an authentication password as the string yourpass:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# authentication-key yourpass
Command |
Description |
---|---|
Specifies authentication type. |
To control how the Open Shortest Path First (OSPF) protocol calculates default metrics for the interface, use the auto-cost command in the appropriate mode. To revert to the default reference bandwidth, use the no form of this command.
auto-cost { reference-bandwidth mbps | disable }
no auto-cost { reference-bandwidth | disable }
reference-bandwidth mbps |
Specifies a rate in Mbps (bandwidth). Range is 1 to 4294967. |
disable |
Assigns a cost based on interface type. |
mbps : 100 Mbps
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
By default OSPF calculates the OSPF metric for an interface according to the bandwidth of the interface.
The OSPF metric is calculated as the mbps value divided by bandwidth, with mbps equal to 108 by default.
If you have multiple links with high bandwidth (such as OC-192), you might want to use a larger number to differentiate the cost on those links. That is, the metric calculated using the default mbps value is the same for all high-bandwidth links.
Recommended usage of cost configuration for OSPF interfaces with high bandwidth is to be consistent: Either explicitly configure (by using the cost command) or choose the default (by using the auto-cost command).
The value set by the cost command overrides the cost resulting from the auto-cost command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the reference value for the auto cost calculation to 1000 Mbps:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# auto-cost reference-bandwidth 1000
Command |
Description |
---|---|
Explicitly specifies the cost of the interface (network) for OSPF path calculation. |
To prevent Multiprotocol Label Switching traffic engineering (MPLS TE) topology information flooded to the network through opaque LSAs, use the capability opaque disable command in the appropriate mode. To restore MPLS TE topology information flooded through opaque LSAs to the network, use the no form of the command.
capability opaque disable
no capability opaque disable
Opaque LSAs are allowed.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. The enable keyword was removed. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The capability opaque disable command prevents flooded MPLS TE information (Types 1 and 4) through opaque LSAs of all scope (Types 9, 10, and 11).
Control opaque LSA support capability must be enabled for OSPF to support MPLS TE.
The MPLS TE topology information is flooded to the area through opaque LSAs by default.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to prevent OSPF from supporting opaque services:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# capability opaque disable
To ignore DN bit in LSAs received from peers in the given VRF and to disable automatic ABR status in that VRF, use the capability vrf-lite command in OSPFv2 VRF configuration mode. To disable ignoring the DN bit in LSAs and to re-enable automatic ABR status in the VRF, use the no form of this command.
capability vrf-lite
no capability vrf-lite
This command has no keywords or arguments.
Disabled
OSPFv2 VRF configuration
Release | Modification |
---|---|
Release 4.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the capability vrf-lite command when CE routers (sometimes called multi-vrf CE routers) are directly connected through interfaces associated with a VRF, but without being connected to other PEs through the MPLS/VPN BGP Backbone. Configure the capability vrf-lite command for CE routers.
When OSPFv2 is enabled in a VRF, the router is always an ABR. With the capability vrf-lite command is enabled, the router becomes an ABR only if it is connected to area 0 (backbone area), and there are other (non-backbone) areas enabled on this router in the given VRF.
Note | Routes may be re-introduced to the VPN backbone when this command is used. |
Task ID | Operation |
---|---|
ospf |
read, write |
This example shows how to enable vrf-lite capability for OSPF instance 100 under vrf1
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#vrf vrf1 RP/0/0/CPU0:router(config-ospf-vrf)#capability vrf-lite
To reset an Open Shortest Path First (OSPF) router process without stopping and restarting it, use the clear ospf process command in EXEC configuration mode.
clear ospf [ process-name [ vrf { vrf-name | all } ] ] process
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only the specified routing process is affected. Otherwise, all OSPF processes are reset. |
vrf |
(Optional) An OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF instance to be reset. |
all |
(Optional) Resets all OSPF VRF instances. |
No default behavior or value
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
The vrf keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When the OSPF router process is reset, OSPF releases all resources allocated, cleans up the internal database, and shuts down and restarts all interfaces that belong to the process.
Note | The clear ospf process command may change the router ID unless the OSPF router ID is explicitly configured through the router-id (OSPF) command. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to reset all OSPF processes:
RP/0/0/CPU0:router# clear ospf process
The following example shows how to reset the OSPF 1 process:
RP/0/0/CPU0:router# clear ospf 1 process
Command |
Description |
---|---|
Configures an OSPF routing process. |
|
Configures a router ID for the OSPF process. |
To clear all routes redistributed from other protocols out of the Open Shortest Path First (OSPF) routing table, use the clear ospf redistribution command in EXEC configuration mode.
clear ospf [ process-name [ vrf { vrf-name | all } ] ] redistribution
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only the specified routing process is affected. Otherwise, all OSPF routes are cleared. |
vrf |
(Optional) OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF instance to be reset. |
all |
(Optional) Resets all OSPF VRF instances. |
No default behavior or value
Release |
Modification |
---|---|
Release 2.0 |
This command was introduced. |
Release 3.3.0 |
The vrf keyword was added. |
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced . |
Release 3.3.0 |
The vrf keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the clear ospf redistribution command to cause the routing table to be read again. OSPF regenerates and sends Type 5 and Type 7 link-state advertisements (LSAs) to its neighbors. If an unexpected route has appeared in the OSPF redistribution, using this command corrects the issue.
Note | Use of this command can cause a significant number of LSAs to flood the network. We recommend that you use this command with caution. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to clear all redistributed routes across all processes from other protocols:
RP/0/0/CPU0:router# clear ospf redistribution
To clear all Open Shortest Path First (OSPF) routes from the OSPF routing table, use the clear ospf routes command in EXEC configuration mode.
clear ospf [ process-name [ vrf { vrf-name | all } ] ] routes
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only the specified routing process is affected. Otherwise, all OSPF routes are cleared. |
vrf |
(Optional) OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF instance to be reset. |
all |
(Optional) Resets all OSPF VRF instances. |
No default behavior or value
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. The topology keyword was replaced with the routes keyword. |
Release 3.3.0 |
The vrf keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to clear all OSPF routes from the OSPF routing table and recompute valid routes. When the OSPF routing table is cleared, OSPF routes in the global routing table are also recalculated.
RP/0/0/CPU0:router# clear ospf routes
Command |
Description |
---|---|
Configures an OSPF routing process. |
To clear the Open Shortest Path First (OSPF) statistics of neighbor state transitions, use the clear ospf statistics command in EXEC configuration mode.
clear ospf [ process-name [ vrf { vrf-name | all } ] ] statistics [ neighbor [ type interface-path-id ] [ip-address] ]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only the specified routing process is affected. Otherwise, all OSPF statistics of neighbor state transitions are cleared. |
vrf |
(Optional) OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF instance to be reset. |
all |
(Optional) Resets all OSPF VRF instances. |
neighbor |
(Optional) Clears the state transition counters of the specified neighbor only. |
type |
(Optional) Interface type. For more information, use the question mark (?) online help function. |
interface-path-id |
(Optional) Physical interface or virtual interface. Use the show interfaces command to see a list of all interfaces currently configured on the router. For more information about the syntax for the router, use the question mark (?) online help function. |
ip-address |
(Optional) IP address of a specified neighbor for whom you want to clear the state transition counter. |
No default behavior or value
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
The vrf keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the clear ospf statistics command to reset OSPF counters. Reset is useful to detect changes in counter values.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to reset the OSPF transition state counters for all neighbors on Packet-over-SONET/SDH (POS) interface 0/2/0/0:
RP/0/0/CPU0:router# clear ospf statistics neighbor POS 0/2/0/0
Command |
Description |
---|---|
Configures an OSPF routing process. |
To clear the Open Shortest Path First (OSPF) statistics per interface, use the clear ospf statistics interface command in EXEC configuration mode.
clear ospf statistics interface type interface-path-id
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
No default behavior or value.
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the clear ospf statistics interface command to reset OSPF counters. Reset is useful to detect changes in counter values.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to reset OSPF statistics for interface POS 0/21/0/0:
RP/0/0/CPU0:router# clear ospf statistics interface POS 0/21/0/0
Command |
Description |
---|---|
Clears the Open Shortest Path First (OSPF) statistics of neighbor state transitions. |
To explicitly specify the interface (network) for Open Shortest Path First (OSPF) path calculation, use the cost command in the appropriate mode. To remove the cost, use the no form of this command.
cost cost
no cost
cost |
Unsigned integer value expressed as the link-state metric. Range is 1 to 65535. |
If this command is not specified in interface configuration mode, then the interface adopts the cost parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the cost parameter specified for the process.
If this command is not specified at any level, then the cost is calculated by the auto-cost command.
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The link-state metric is advertised as the link cost in the router link advertisement. Cisco IOS XR software does not support type of service (ToS), so you can assign only one cost for each interface.
In general, the path cost is calculated using the following formula:
108 / bandwidth (the default auto cost is set to 100 Mbps)
This calculation is the default reference bandwidth used by the auto-costing calculation which establishes the interface auto-cost The auto-cost command can set this reference bandwidth to some other value. The cost command is used to override the auto-costing calculated default value for interfaces.
Using this formula, the default path cost is 1 for any interface that has a link bandwidth of 100 Mbps or higher. If this value does not suit the network, configure the reference bandwidth for auto calculating costs based on the link bandwidth.
The value set by the cost command overrides the cost resulting from the auto-cost (OSPF) command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the cost value to 65 for GigabitEthernet interface 0/1/0/1:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# cost 65
Command |
Description |
---|---|
Controls how the OSPF protocol calculates default metrics for the interface. |
To apply higher cost than the normal interface cost when the cumulative bandwidth of a bundle interface goes below the threshold specified and to revert to the original cost if the cumulative bandwidth goes above the configured threshold, use the cost-fallback command. To remove the cost-fallback, use the no form of this command.
cost-fallback cost threshold bandwidth
no cost-fallback
cost threshold |
Unsigned integer value expressed as the link-state metric. Range is 1 to 65535, but typically, cost-fallback value is supposed to be set to a value higher than the normal cost. |
bandwidth |
Unsigned integer value expressed in Mbits per second. Range is 1 to 4294967. |
If this command is not specified in interface configuration mode, the currently effective interface cost takes effect even when the cumulative bandwidth goes down below the maximum bandwidth. Unlike the interface cost command, this cost-fallback command is available only under interface configuration mode; it is not available in area or process level. Unlike other interface specific parameters, no inheritance will take place from area or process level if this command is not specified at interface level.
Interface configuration
Release |
Modification |
---|---|
Release 3.6.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The fallback cost must be set to a higher value than the normal interface cost. The motivation of setting the fallback cost is to cost out an interface or disfavor an interface without shutting it down when its cumulative bandwidth goes below the user specified threshold, so that the traffic can take an alternative path. The normal interface cost will take over when the cumulative bandwidth reaches or exceeds user-specified threshold.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the cost-fallback value for Packet-over-SONET/SDH (POS):
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 100 RP/0/0/CPU0:router(config-ospf)# router-id 2.2.2.2 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface bundle-pos1 RP/0/0/CPU0:router(config-ospf-ar-if)# cost-fallback 1000 threshold 300
Command |
Description |
---|---|
Controls how the OSPF protocol calculates default metrics for the interface. |
|
Specifies the cost of the interface (network) for OSPF path calculation. |
To filter outgoing link-state advertisements (LSAs) to an Open Shortest Path First (OSPF) interface, use the database-filter all out command in the appropriate mode. To restore the forwarding of LSAs to the interface, use the disable form of the command.
database-filter all out [ disable | enable ]
disable |
(Optional) Disables filtering. |
enable |
(Optional) Enables filtering. |
The database filter is disabled.
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Release |
Modification |
---|---|
Release 6.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Use the database-file all out command to perform the same function that the neighbor database-filter all out command performs on a neighbor basis.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to prevent flooding of OSPF LSAs to broadcast, nonbroadcast, and point-to-point networks reachable through GigabitEthernet interface 0/1/0/1:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# database-filter all out
To set the interval after which a neighbor is declared dead when no hello packets are observed, use the dead-interval command in the appropriate mode. To return to the default time, use the no form of this command.
dead-interval seconds
no dead-interval
seconds |
Integer that specifies the interval (in seconds). Range is 1 to 65535. The value must be the same for all nodes on the network. |
If this command is not specified in interface configuration mode, then the interface adopts the dead interval parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the dead interval parameter specified for the process.
If this command is not specified at any level, then the dead interval is four times the interval set by the hello-interval (OSPF) command.
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The dead interval value must be the same for all routers and access servers on a specific network.
If the hello interval is configured, the dead interval value must be larger than the hello interval value. The dead interval value is usually configured four times larger than the hello interval value.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the OSPF dead interval to 40 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# dead-interval 40
Command |
Description |
---|---|
Specifies the interval between hello packets that the Cisco IOS XR software sends on the interface. |
To specify a cost for the default summary route sent into a stub area or not-so-stubby area (NSSA), use the default-cost command in area configuration mode. To remove the assigned default route cost, use the no form of this command.
default-cost cost
no default-cost cost
cost |
Cost for the default summary route used for a stub or NSSA area. The acceptable value is a 24-bit number. |
cost : 1
Area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the default-cost command only on an Area Border Router (ABR) attached to a stub or an NSSA area.
In all routers and access servers attached to the stub area, the area should be configured as a stub area using the stub command in the area submode. Use the default-cost command only on an ABR attached to the stub area. The default-cost command provides the metric for the summary default route generated by the ABR into the stub area.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to assign a default cost of 20 to a stub area. The GigabitEthernet interface 0/4/0/3 is also configured in the stub area):
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# area 10.15.0.0 RP/0/0/CPU0:router(config-ospf-ar)# stub RP/0/0/CPU0:router(config-ospf-ar)# default-cost 20 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/4/0/3
Command |
Description |
---|---|
Defines an area as a stub area. |
To generate a default external route into an Open Shortest Path First (OSPF) routing domain, use the default-information originate command in the appropriate mode. To disable this feature, use the no form of this command.
default-information originate [always] [ metric metric-value ] [ metric-type type-value ] [ route-policy policy-name ] [ tag tag-value ]
no default-information originate
always |
(Optional) Always advertises the default route regardless of whether the routing table has a default route. |
metric metric-value |
(Optional) Specifies the metric used for generating the default route. The default metric value is 1. Range is 1 to 16777214. |
metric-type type-value |
(Optional) Specifies the external link type associated with the default route advertised into the OSPF routing domain. It can be one of the following values: 1—Type 1 external route 2—Type 2 external route |
tag tag-value |
(Optional) 32-bit dotted-decimal value attached to each external route. This is not used by the OSPF protocol itself. It may be used to communicate information between autonomous system boundary routers (ASBRs). If a tag is not specified, then the configured OSPF process number is used. |
route-policy policy-name |
(Optional) Specifies that a routing policy be used and the routing policy name. |
When you do not use this command in router configuration mode, no default external route is generated into an OSPF routing domain.
metric-value : 1
type-value : 2
tag-value: configured OSPF process number
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. The policy keyword was changed to route-policy . |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Whenever you use the redistribute or default-information originate command to redistribute routes into an OSPF routing domain, the software automatically becomes an Autonomous System Boundary Router (ASBR). However, an ASBR does not, by default, generate a default route into the OSPF routing domain. The software still must have a default route for itself before it generates one, except when you have specified the always keyword.
The default-information originate route-policy attach point conditionally injects the default route 0.0.0.0/0 into the OSPF link-state database, and is done by evaluating the attached policy. If any routes specified in the policy exist in the global RIB, then the default route is inserted into the link-state database. If there is no match condition specified in the policy, the policy passes and the default route is generated into the link-state database.
For information about the default-information originate attach point, see the OSPF Policy Attach Points section in the Implementing Routing Policy chapter in Cisco IOS XR Routing Configuration Guide for the Cisco XR 12000 Series Router.
For information about routing policies, see the Routing Policy Commands chapter in the Cisco IOS XR Routing Command Reference for the Cisco XR 12000 Series Router.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to specify a metric of 100 for the default route redistributed into the OSPF routing domain and an external metric type of Type 1:
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 109 RP/0/0/CPU0:router(config-ospf)#redistribute igrp 108 metric 100 RP/0/0/CPU0:router(config-ospf)#default-information originate metric 100 metric-type 1
Command |
Description |
---|---|
Redistributes routes from one routing domain into a specified OSPF process. |
To set default metric values for routes redistributed from another protocol into the Open Shortest Path First (OSPF) protocol, use the default-metric command in the appropriate mode. To return to the default state, use the no form of this command.
default-metric value
no default-metric value
value |
Default metric value appropriate for the specified routing protocol. Range is 1 to 16777214. |
Built-in, automatic metric translations, as appropriate for each routing protocol.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the default-metric command with the redistribute command to cause the current routing protocol to use the same metric value for all redistributed routes. A default metric helps solve the problem of redistributing routes with incompatible metrics. Whenever metrics do not convert, use a default metric to provide a reasonable substitute and enable the redistribution to proceed.
The default-metric value configured in OSPF configuration does not apply to connected routes that are redistributed to OSPF using the redistribute connected command. To set a non-default metric for connected routes, configure OSPF with the redistribute connected metric metric-value command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to advertise Intermediate System-to-Intermediate System (IS-IS) protocol-derived routes into OSPF and assign a metric of 10:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# default-metric 10 RP/0/0/CPU0:router(config-ospf)# redistribute isis IS-IS_isp
Command |
Description |
---|---|
Redistributes routes from one routing domain into a specified OSPF process. |
To configure the Open Shortest Path First (OSPF) protocol to treat the interface as an OSPF demand circuit, use the demand-circuit command in the appropriate mode. To remove the demand circuit designation from the interface, use the no form of this command.
demand-circuit [ disable | enable ]
no demand-circuit
disable |
(Optional) Disables the interface as an OSPF demand circuit. |
enable |
(Optional) Enables the interface as an OSPF demand circuit. |
If this command is not specified in interface configuration mode, then the interface adopts the demand circuit parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the demand circuit parameter specified for the process.
If this command is not specified at any level, then the circuit is not a demand circuit.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
On point-to-point interfaces, only one end of the demand circuit must be configured with this command. Periodic hello messages are suppressed and periodic refreshes of link-state advertisements (LSAs) do not flood the demand circuit. Use the demand-circuit command to allow the underlying data link layer to be closed when the topology is stable. In point-to-multipoint topology, only the multipoint end must be configured with this command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the configuration for an OSPF demand circuit:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# router ospf 1 RP/0/RP0/CPU0:router(config-ospf)# demand-circuit
To specify that down bits should be ignored, use the disable-dn-bit-check command in VPN routing and forwarding (VRF) configuration mode. To specify that down bits should be considered, use the no form of this command.
disable-dn-bit-check
no disable-dn-bit-check
Down bits are considered.
VRF configuration mode
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to specify that down bits be ignored:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# vrf v1 RP/0/0/CPU0:router(config-ospf-vrf)# disable-dn-bit-check
To define an administrative distance, use the distance command in an appropriate configuration mode. To remove the distance command from the configuration file and restore the system to its default condition in which the software removes a distance definition, use the no form of this command.
distance weight [ ip-address wildcard-mask [access-list-name] ]
no distance weight ip-address wildcard-mask [access-list-name]
weight |
Administrative distance. Range is 10 to 255. Used alone, the weight argument specifies a default administrative distance that the software uses when no other specification exists for a routing information source. Routes with a distance of 255 are not installed in the routing table. lists the default administrative distances. Table 1 |
ip-address |
(Optional) IP address in four-part, dotted-decimal notation. |
wildcard-mask |
(Optional) Wildcard mask in four-part, dotted decimal format. A bit set to 1 in the mask argument instructs the software to ignore the corresponding bit in the address value. |
access-list-name |
(Optional) Name of an IP access list to be applied to incoming routing updates. |
If this command is not specified, then the administrative distance is the default, as specified in Table 1.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
An administrative distance is an integer from 10 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means that the routing information source cannot be trusted at all and should be ignored. Weight values are subjective; no quantitative method exists for choosing weight values.
If an access list is used with this command, it is applied when a network is being inserted into the routing table. This behavior allows you to filter networks based on the IP prefix supplying the routing information. For example, you could filter possibly incorrect routing information from networking devices not under your administrative control.
The order in which you enter distance commands can affect the assigned administrative distances in unexpected ways (see the “Examples” section for further clarification).
Route Source |
Default Distance |
---|---|
Connected interface |
0 |
Static route out on interface |
0 |
State route to next-hop |
1 |
EIGRP Summary Route |
5 |
External BGP |
20 |
Internal EIGRP |
90 |
OSPF |
110 |
IS-IS |
115 |
RIP version 1 and 2 |
120 |
External EIGRP |
170 |
Internal BGP |
200 |
Unknown |
255 |
Task ID |
Operations |
---|---|
ospf |
read, write |
In the following example, the router ospf command sets up OSPF routing instance1. The first distance command sets the default administrative distance to 255, which instructs the software to ignore all routing updates from networking devices for which an explicit distance has not been set. The second distance command sets the administrative distance for all networking devices on the Class C network 192.168.40.0 0.0.0.255 to 90.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# distance 255 RP/0/0/CPU0:router(config-ospf)# distance 90 192.168.40.0 0.0.0.255
Command |
Description |
---|---|
distance bgp |
Allows the use of external, internal, and local administrative distances that could be a better route to a BGP node. |
distance ospf |
Allows the use of external, internal, and local administrative distances that could be a better route to an OSPF node. |
Configures the OSPF routing process. |
To define Open Shortest Path First (OSPF) route administrative distances based on route type, use the distance ospf command in router configuration mode. To restore the default value, use the no form of this command.
distance ospf { intra-area | inter-area | external } distance
no distance ospf
intra-area | inter-area | external |
Sets the type of area. It can be one of the following values: intra-area —All routes within an area. inter-area —All routes from one area to another area. external —All routes from other routing domains, learned by redistribution. Any combination of the above areas is allowed. |
distance |
Route administrative distance. |
distance : 110
Router configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You must specify one of the keywords.
Use the distance ospf command to perform the same function as the distance command used with an access list. However, the distance ospf command sets a distance for an entire group of routes, rather than a specific route that passes an access list.
A common reason to use the distance ospf command is when you have multiple OSPF processes with mutual redistribution, and you want to prefer internal routes from one over external routes from the other.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to change the external distance to 200, making the route less reliable:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# redistribute ospf 2 RP/0/0/CPU0:router(config-ospf)# distance ospf external 200 RP/0/0/CPU0:router(config-ospf)# exit RP/0/0/CPU0:router(config)# router ospf 2 RP/0/0/CPU0:router(config-ospf)# redistribute ospf 1 RP/0/0/CPU0:router(config-ospf)# distance ospf external 200
Command |
Description |
---|---|
Defines an administrative distance. |
To filter networks received or transmitted in Open Shortest Path First (OSPF) updates, use the distribute-list command in the appropriate mode. To change or cancel the filter, use the no form of this command.
distribute-list { access-list-name { in | out [ bgp number | connected | ospf instance | static ] } | route-policy route-policy-name in }
no distribute-list { access-list-name { in | out } | route-policy route-policy-name in }
access-list-name |
Standard IP access list name. The list defines which networks are to be received and which are to be suppressed in routing updates. |
in |
Applies the access list or route-policy to incoming routing updates. |
out |
Applies the access list to outgoing routing updates. The out keyword is available only in router configuration mode. |
bgp |
(Optional) Applies the access list to BGP routes. |
connected |
(Optional) Applies the access list to connected routes. |
ospf |
(Optional) Applies the access list to OSPF routes (not the current OSPF process). |
static |
(Optional) Applies the access list to statically configured routes. |
route-policy route-policy-name |
Specifies the route-policy to filter OSPF prefixes. |
If this command is not specified in interface configuration mode, then the interface adopts the distribute list parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the distribute list parameter specified for the process.
If this command is not specified at any level, then the distribute list is disabled.
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added in the VRF configuration mode. |
Release 3.4.1 |
This command was added in the multi-area interface configuration mode. |
Release 4.2.1 |
The route-policy route-policy-name keyword and argument were added to allow use of route policies to filter OSPF prefixes. |
Release 4.3.1 |
Support was added for "if tag..." statements in distribute-list in route-policy. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the distribute-list command to limit which OSPF routes are installed on this router. The distribute-list command does not affect the OSPF protocol itself.
The distribute-list in is configurable at instance (process), area, and interface levels. Regular OSPF configuration inheritance applies. Configuration is inherited from instance > area > interface levels.
Use the route-policy route-policy-name keyword and argument to allow use of route policies to filter OSPF prefixes.
Note | Either an access-list, or a route-policy can be used in a single command, not both. Configuring the command with access-list removes the route-policy configuration, and vice versa. |
The "if tag..." statements can be used in distribute-list in route-policy. The matching on route tag supports operators "eq/ge/is/le". Operator "in" is not supported.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to prevent OSPF routes from the 172.17.10.0 network from being installed if they are learned in area 0:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# ipv4 access-list 3 RP/0/0/CPU0:router(config-ipv4-acl)# deny 172.17.10.0 0.0.0.255 RP/0/0/CPU0:router(config-ipv4-acl)# permit any any ! RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# distribute-list 3 in RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3
To specify the Open Shortest Path First (OSPF) VPN routing and forwarding (VRF) domain ID, use the domain-id command in VRF configuration mode. To remove an OSPF VRF domain ID, use the no form of this command.
domain-id [secondary] type [ 0005 | 0105 | 0205 | 8005 ] value value
no domain-id [secondary] type [ 0005 | 0105 | 0205 | 8005 ] value value
secondary |
(Optional) OSPF secondary domain ID. |
type |
Primary OSPF domain ID in hex format. |
value value |
OSPF domain ID value in hex format (six octets). |
No domain ID is specified.
VRF configuration mode
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
An OSPF domain id must be explicitly configured. The OSPF domain ID helps OSPF determine how to translate a prefix received through Border Gateway Protocol (BGP) from the remote provider edge (PE). If the domain IDs match, OSPF generates a Type 3 link state advertisement (LSA). If the domain IDs do not match, OSPF generates a Type 5 LSA.
There is only one primary domain ID. There can be multiple secondary domain IDs.
Note | When an IOS XR router and an IOS router are configured as peers, the two Domain IDs must match. Manually configure the IOS XR Domain ID value to match the IOS default Domain ID value. This ensures that the routes have route code "OIA" because they are learned as inter-area routes. If the Domain IDs do not match, the routes have route code, "O-E2" because they are learned as external routes. Use the show ip ospf command to get the OSPF Domain ID from the IOS router. Then, set the IOS XR Domain ID to the same value using the domain-id command. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to specify a domain ID:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf o1 RP/0/0/CPU0:router(config-ospf)# vrf v1 RP/0/0/CPU0:router(config-ospf-vrf)# domain-id type 0105 value AABBCCDDEEFF
To specify the Open Shortest Path First (OSPF) VPN routing and forwarding (VRF) domain tag, use the domain-tag command in VRF configuration mode. To remove an OSPF VRF domain tag, use the no form of this command.
domain-tag tag
no domain-tag
tag |
OSPF domain tag as a 32-bit value. The valid range is 0 to 4294967295. |
No OSPF VRF domain tag is specified.
VRF configuration mode
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The domain tag is added to any Type 5 link state advertisements (LSAs) generated as a result of VPN-IP routes received from Border Gateway Protocol (BGP). The domain-tag is derived from BGP autonomous system number (ASN).
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to specify the domain tag:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf o1 RP/0/0/CPU0:router(config-ospf)# domain-tag 234
To enable IP fast reroute loop-free alternate (LFA) computation, use the fast-reroute command in the appropriate OSPF configuration mode. To disable the IP fast reroute loop-free alternate computation, use the no form of this command.
To disable loop-free alternate computation that is enabled on a higher level, use the fast-reroute command with disable keyword.
fast-reroute { per-link | per-prefix } [disable]
no fast-reroute
per-link |
Enables per-link loop-free alternate computation. |
per-prefix |
Enables per-prefix loop-free alternate computation. |
disable |
(Optional) Disables loop-free alternate computation that was enabled on a higher level. |
IP fast-reroute LFA computation is disabled.
Area configuration
Interface configuration
Router configuration
VRF configuration
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced and replaced the ipfrr lfa command. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Only one mode of computation can be configured on an interface - per-link or per-prefix. Different modes of computations can be enabled on different interfaces; one set of interface using per-link and other set using per-prefix computation. Based on the outgoing interface of the primary path, per-link or per-prefix backup path will be computed.
Task ID | Operation |
---|---|
ospf |
read, write |
RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/3/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# fast-reroute per-link
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 1 RP/0/0/CPU0:router(config-ospf)#area 0 RP/0/0/CPU0:router(config-ospf-ar)#fast-reroute per-prefix
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 1 RP/0/0/CPU0:router(config-ospf)#area 0 RP/0/0/CPU0:router(config-ospf-ar)#fast-reroute per-prefix RP/0/0/CPU0:router(config-ospf-ar)#interface GigabitEthernet 0/3/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)#fast-reroute disable
To excludes specified interface to be used as a backup during (IPFRR) loop-free alternate (LFA) computation, use the fast-reroute per-link exclude interface command, in the appropriate OSPF configuration mode. To disable this feature, use the no form of this command.
fast-reroute per-link exclude interface type interface-path-id
no fast-reroute per-link exclude interface type interface-path-id
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
No interfaces are excluded.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to exclude an interface from IP fast reroute loop-free alternate (LFA) computation:
RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf-ar-if)# fast-reroute per-link exclude interface GigabitEthernet 0/3/2/1
Command |
Description |
---|---|
Enables IP fast reroute loop-free alternate (LFA) computation. |
To exclude interface to be used as a backup path from fast-reroute loop-free alternate per-prefix computation, use the fast-reroute per-prefix exclude interface command in the appropriate OSPF configuration mode. To disable this feature, use the no form of this command.
fast-reroute per-prefix exclude interface type interface-path-id
no fast-reroute per-prefix exclude interface type interface-path-id
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
For more information about the syntax for the router, use the question mark (?) online help function. |
No interfaces are excluded.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Backup paths via the excluded interfaces will not be computed.
Task ID | Operation |
---|---|
ospf |
read, write |
This example shows how to exclude interface POS0/6/0/1 from being used as a backup path:
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#fast-reroute per-prefix exclude interface GigabitEthernet 0/6/0/1
To add interfaces to the LFA candidate list, use the fast-reroute per-prefix lfa-candidate command in interface configuration mode. To disable this feature, use the no form of this command.
fast-reroute per-prefix lfa-candidate [interface-name]
no fast-reroute per-prefix lfa-candidate [interface-name]
interface-name |
Specifies name of the interface to add to the LFA candidate list. |
No interfaces are added to the candidate list.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
ospf |
read, write |
This example shows how to add an interface to LFA candidates:
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#fast-reroute per-prefix lfa-candidate interface GigabitEthernet 0/6/0/0
To configure fast-reroute per-prefix remote loop-free alternate (rLFA) computation for an OSPFv2 process, use the fast-reroute per-prefix remote-lfa command in the appropriate OSPF configuration mode. To disable this feature, use the no form of this command.
fast-reroute per-prefix remote-lfa { disable | maximum-cost path-cost | tunnel mpls-ldp }
no fast-reroute per-prefix remote-lfa
remote-lfa |
Enables remote LFA backup computation |
maximum-cost path-cost |
Sets the cost option to limit the range of remote LFAs. Range for path-cost is 1 to 4294967295. |
tunnel mpls-ldp |
Enables remote LFA computation using tunnel interfaces. |
disable |
Selectively disables remote LFA calculation under one or more areas. |
Remote LFA FRR computation is disabled.
Router configuration
Area configuration
Interface configuration
Release | Modification |
---|---|
Release 4.3.1 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Fast-reroute per-prefix LFA must be enabled for remote LFA to be operational. The OSPF configuration hierarchy at process level and area level are applicable for remote LFA configuration. For example, it is possible to enable remote-LFA for all OSPF areas and selectively disable (using disable keyword) the computation under one or more area.
Task ID | Operation |
---|---|
ospf |
read, write |
RP/0/0/CPU0:router(config)#router ospf 1 RP/0/0/CPU0:router(config-ospf)#fast-reroute per-prefix remote-lfa tunnel mpls-ldp
RP/0/0/CPU0:router(config)#router ospf 1 RP/0/0/CPU0:router(config-ospf)#fast-reroute per-prefix remote-lfa maximum-cost 2
Command | Description |
| Enables IP fast reroute loop-free alternate (LFA) computation. |
To restrict the backup interfaces to those that are present on the LFA candidate list, use the fast-reroute per-prefix use-candidate-only command in router OSPF configuration mode. To disable this feature, use the no form of this command.
fast-reroute per-prefix use-candidate-only [ enable | disable ]
fast-reroute per-prefix use-candidate-only
enable |
Enables backup selection from candidate-list only. |
disable |
Disables backup selection from candidate-list only. |
Disabled.
Router OSPF configuration
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
ospf |
read, write |
This example shows how to restrict the backup interfaces to those that are present on the LFA candidate list:
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#fast-reroute per-prefix use-candidate-only
To suppress the unnecessary flooding of link-state advertisements (LSAs) in stable topologies, use the flood-reduction command in the appropriate mode. To remove this functionality from the configuration, use the no form of this command.
flood-reduction [ enable | disable ]
no flood-reduction [ enable | disable ]
enable |
(Optional) Turns on this functionality at a specific level. |
disable |
(Optional) Turns off this functionality at a specific level. |
If this command is not specified in interface configuration mode, then the interface adopts the flood reduction parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the flood reduction parameter specified for the process.
If this command is not specified at any level, then flood reduction is disabled.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added in the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
All routers supporting the OSPF demand circuit are compatible and can interact with routers supporting flooding reduction.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to reduce the flooding of unnecessary LSAs for area 0:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# flood-reduction
Command |
Description |
---|---|
Displays OSPF-related interface information. |
|
Displays OSPF neighbor information on an individual interface basis. |
To specify the interval between consecutive hello packets that are sent on the Open Shortest Path First (OSPF) interface, use the hello-interval command in the appropriate mode. To return to the default time, use the no form of this command.
hello-interval seconds
no hello-interval
seconds |
Interval (in seconds). The value must be the same for all nodes on a specific network. Range is 1 to 65535. |
If this command is not specified in interface configuration mode, then the interface adopts the hello interval parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the hello interval parameter specified for the process.
If this command is not specified at any level, then the hello interval is 10 seconds (broadcast) or 30 seconds (non-broadcast).
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced.. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The hello interval value is advertised in the hello packets. The shorter the hello interval, the faster topological changes are detected, but more routing traffic occurs. This value must be the same for all routers and access servers on a specific network.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the interval between hello packets to 15 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# hello-interval 15
Command |
Description |
---|---|
Sets the time period for which hello packets are suspended before neighbors declare the router down. |
To suppress the sending of syslog messages when the router receives link-state advertisement (LSA) Type 6 multicast Open Shortest Path First (MOSPF) packets, which are unsupported, use the ignore lsa mospf command in an appropriate configuration mode. To restore the sending of syslog messages, use the no form of this command.
ignore lsa mospf
no ignore lsa mospf
This command has no keywords or arguments.
When you do not specify this command in router configuration mode, each MOSPF packet received by the router causes the router to send a syslog message.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Cisco routers do not support LSA Type 6 (MOSPF), and they generate syslog messages if they receive such packets. If the router is receiving many MOSPF packets, you might want to configure the router to ignore the packets and thus prevent a large number of syslog messages.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the router to suppress the sending of syslog messages when it receives MOSPF packets:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# ignore lsa mospf
To define the interfaces on which the Open Shortest Path First (OSPF) protocol runs, use the interface command in area configuration mode. To disable OSPF routing for interfaces, use the interface form of this command.
interface type interface-path-id
no interface type interface-path-id
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtualinterface.
For more information about the syntax for the router, use the question mark (?) online help function. |
When you do not specify this command in configuration mode, OSPF routing for interfaces is not enabled.
Area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the interface command to associate a specific interface with an area. The interface remains associated with the area even when the IP address of the interface changes.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how the OSPF routing process 109 defines four OSPF areas (0, 2, 3, and 10.9.50.0), and associates an interface with each area:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 4/0/0/3 ! RP/0/0/CPU0:router(config-ospf)# area 2 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3 ! RP/0/0/CPU0:router(config-ospf)# area 3 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 3/0/0/2 ! RP/0/0/CPU0:router(config-ospf)# area 10.9.50.0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 3/0/0/1
To configure the router to send a syslog message when the state of an Open Shortest Path First (OSPF) neighbor changes, use the log adjacency changes command in router configuration mode. To turn off this function, use the disable keyword. To log all state changes, use the detail keyword.
log adjacency changes { detail | disable }
detail |
Provides all (DOWN, INIT, 2WAY, EXSTART, EXCHANGE, LOADING, FULL) adjacency state changes. |
disable |
Disables sending adjacency change messages. |
The router sends a syslog message when the state of an OSPF neighbor changes.
Router configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The detail and disable keywords were changed from optional to required. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the log adjacency changes command to display high-level changes to the state of the peer relationship. Configure this command if you want to know about OSPF neighbor changes.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the software to send a syslog message for any OSPF neighbor state changes:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# log adjacency changes detail
To enable advertising loopback as stub networks, use the loopback stub-network command in an appropriate configuration mode. To disable advertising loopback as stubnetworks, use the no form of this command.
loopback stub-network [ enable | disable ]
no loopback stub-network
enable |
(Optional) Enables advertising loopbacks as stub networks. |
disable |
(Optional) Disables advertising loopbacks as stub networks. |
By default, OSPF advertises loopbacks as stub hosts.
OSPF interface configuration
OSPF router configuration
OSPF area configuration
Release | Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
In the interface submode, the command can be enabled only on loopback interfaces.
Task ID | Operation |
---|---|
ospf |
read, write |
The following example shows how to enable advertising loopback as a stub network, under OSPF interface configuration:
RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#loopback stub-network enable
Command | Description |
show ospf interfaceDisplays Open Shortest Path First (OSPF) interface information. |
|
To limit the number of nonself-generated link-state advertisements (LSAs) that an Open Shortest Path First (OSPF) routing process can keep in the OSPF link-state database (LSDB), use the max-lsa command in router configuration mode. To remove the limit of non self-generated LSAs that an OSPF routing process can keep in the OSPF LSDB, use the no form of this command.
max-lsa max [threshold] [warning-only] [ ignore-time value ] [ ignore-count value ] [ reset-time value ]
no max-lsa max [threshold] [warning-only] [ ignore-time value ] [ ignore-count value ] [ reset-time value ]
max |
Maximum number of nonself-generated LSAs the OSPF process can keep in the OSPF LSBD. |
threshold |
(Optional) The percentage of the maximum LSA number, as specified by the maximum-number argument, at which a warning message is logged. The default is 75 percent. |
warning-only |
(Optional) Specifies that only a warning message is sent when the maximum limit for LSAs is exceeded. Disabled by default. |
ignore-time value |
(Optional) Specifies the time, in minutes, to ignore all neighbors after the maximum limit of LSAs has been exceeded. The default is 5 minutes. |
ignore-count value |
(Optional) Specifies the number of times the OSPF process can consecutively be placed into the ignore state. The default is 5 times. |
reset-time value |
(Optional) Specifies the time, in minutes, after which the ignore count is reset to zero. The default is 2 times ignore-time . |
Disabled
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This command allows you to protect the OSPF routing process from the large number of received LSAs that can result from a misconfiguration on another router in the OSPF domain (for example, the redistribution of a large number of IP prefixes to OSPF).
When this feature is enabled, the router keeps count of the number of all received (nonself-generated) LSAs. When the configured threshold value is reached, an error message is logged. When the configured max number of received LSAs is exceeded, the router stops accepting new LSAs.
If the count of received LSAs is higher than the configured max number after one minute, the OSPF process disables all adjacencies in the given context and clears the OSPF database. This state is called the ignore state. In this state, all OSPF packets received on all interfaces belonging to the OSPF instance are ignored and no OSPF packets are generated on its interfaces. The OSPF process remains in the ignore state for the duration of the configured ignore-time . When the ignore-time expires, the OSPF process returns to normal operation and starts building adjacencies on all its interfaces.
To prevent the OSPF instance from endlessly oscillating between its normal state and the ignore state, as a result of the LSA count immediately exceeding the max number again after it returns from the ignore state, the OSPF instance keeps a count of how many times it has been in the ignore state. This counter is called the ignore-count . If the ignore-count exceeds its configured value, the OSPF instance remains in the ignore state permanently.
To return the OSPF instance to its normal state, you must issue the clear ip ospf command. The ignore-count is reset to zero if the LSA count does not exceed the max number again during the time configured by the reset-time keyword.
If you use the warning-only keyword, the OSPF instance never enters the ignore state. When LSA count exceeds the max number, the OSPF process logs an error message and the OSPF instance continues in its normal state operation.
Task ID |
Operations |
---|---|
ospf |
read, write |
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 0 RP/0/0/CPU0:router(config-ospf)# max-lsa 12000 RP/0/0/CPU0:router(config-ospf)# vrf V1 RP/0/0/CPU0:router(config-ospf)# max-lsa 1000
The following example shows how to display the current status of the OSPF instance:
RP/0/0/CPU0:router# show ospf 0
Routing Process "ospf 0" with ID 10.0.0.2
NSR (Non-stop routing) is Disabled
Supports only single TOS(TOS0) routes
Supports opaque LSA
It is an area border router
Maximum number of non self-generated LSA allowed 12000
Current number of non self-generated LSA 1
Threshold for warning message 75%
Ignore-time 5 minutes, reset-time 10 minutes
Ignore-count allowed 5, current ignore-count 0
Command |
Description |
---|---|
Displays general information about Open Shortest Path First (OSPF) routing processes. |
To configure the Open Shortest Path First (OSPF) protocol to signal other networking devices not to prefer the local router as an intermediate hop in their shortest path first (SPF) calculations, use the max-metric command in router configuration mode. To disable this function, use the no form of this command.
max-metric router-lsa [ external-lsa overriding metric ] [ include-stub ] [ on-proc-migration ] [ on-proc-restart ] [ on-startup ] [ on-switchover ] [ wait-for-bgp ] [ summary-lsa ]
no max-metric router-lsa
router-lsa |
Always originates router link-state advertisements (LSAs) with the maximum metric. |
||
external-lsa overriding metric |
(Optional) Overrides the external-lsa metric with the max-metric value.The overriding metric argument specifies the number of in-summary-LSAs. The range is 1 to 16777215>. The default is 16711680. |
||
include-stub |
(Optional) Advertises stub links in router-LSA with the max-metric value (0xFFFF). |
||
on-proc-migration time |
(Optional) Sets the maximum metric temporarily after a process migration to originate router-LSAs with the max-metric value. The time range is 5 to 86400 seconds. |
||
on-proc-restart time |
(Optional) Sets the maximum metric temporarily after a process restart to originate router-LSAs with the max-metric value. The time range is 5 to 86400 seconds. |
||
on-startup time |
(Optional) Sets the maximum metric temporarily after a reboot to originate router-LSAs with the max-metric value. The time range is 5 to 86400 seconds. |
||
on-switchover time |
|
||
wait-for-bgp |
(Optional) Causes OSPF to originate router LSAs with the maximum metric and allows Border Gateway Protocol (BGP) to decide when to start originating router LSAs with a normal metric instead of the maximum metric. |
||
summary-lsa |
(Optional) specifies the number of in summary-LSAs. The range is 1 to 16777215. The default is 16711680. |
Router LSAs are originated with normal link metrics.
overriding-metric :16711680
Router configuration
VRF configuration
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the max-metric command to cause the software to originate router LSAs with router link metrics set to LSInfinity (0XFFFF). This feature can be useful in Internet backbone routers that run both OSPF and BGP because OSPF converges more quickly than BGP and may begin attracting traffic before BGP has converged, resulting in dropped traffic.
If this command is configured, the router advertises its locally generated router LSAs with a metric of 0XFFFF. This action allows the router to converge but not attract transit traffic if there are better, alternative paths around this router. After the specified announce-time value or notification from BGP has expired, the router advertises the local router LSAs with the normal metric (interface cost).
If this command is configured with the on-startup keyword, then the maximum metric is temporarily set only after reboot is initiated. If this command is configured without the on-startup keyword, then the maximum metric is permanently used until the configuration is removed.
If the include-stub keyword is enabled, the stub-links in the router LSA will be sent with the max-metric. If the summary-lsa keyword is enabled, all self-generated summary LSAs will have a metric set to 0xFF0000, unless the metric value is specified with the max-metric value parameter. If the external-lsa keyword is enabled, all self-generated external LSAs will have a metric set to 0xFF0000, unless the metric value is specified with the max-metric value parameter.
This command might be useful when you want to connect a router to an OSPF network, but do not want real traffic flowing through it if there are better, alternative paths. If there are no alternative paths, this router still accepts transit traffic as before.
Some cases where this command might be useful are as follows:
Note | For older OSPF implementations (RFC 1247), router links in received router LSAs with a metric and cost of LSInfinity are not used during SPF calculations. Hence, no transit traffic is set to the routers originating such router LSAs. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure OSPF to originate router LSAs with the maximum metric until BGP indicates that it has converged:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# max-metric router-lsa on-startup wait-for-bgp
To limit the number of interfaces that can be configured for an Open Shortest Path First (OSPF) process, use the maximum interfaces command in the appropriate mode. To return to the default limit, use the no form of this command.
maximum interfaces number-interfaces
no maximum interfaces
number-interfaces |
Number of interfaces. Range is 1 to 4294967295. |
If the command is not specified, the default is 1024.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 4.1.1 |
The range for number of interfaces was changed to 1 to 4294967295 from 1 to 1024. The default number of interfaces was changed to 1024 from 255. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the maximum interface command to increase or decrease the limit on the number of interfaces configured for an OSPF process.
You cannot configure a limit lower than the number of interfaces currently configured for the OSPF process. To lower the limit, remove interfaces from the OSPF configuration until the number of configured interfaces is at or below the desired limit. You may then apply the new, lower limit.
Task ID |
Operations |
---|---|
ospf |
read, write |
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# maximum interfaces 1500
Command |
Description |
---|---|
Displays OSPF interface information. |
To control the maximum number of parallel routes that the Open Shortest Path First (OSPF) protocol can support, use the maximum paths command in an appropriate configuration mode. To remove the maximum paths command from the configuration file and restore the system to its default condition with respect to the routing protocol, use the no form of this command.
maximum paths maximum-routes-number
no maximum paths
maximum-routes-number |
Maximum number of parallel routes that OSPF can install in a routing table. Range is 1 to 64.
|
16 paths
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The default value for maximum-path depends on the platform supported maximum-path value. Any custom value you define for the maximum-path parameter must be within the maximum value supported by platform. The configuration will be rejected if the value you have specified is more then what the platform supports.
When the maximum number of parallel routes is reduced, all existing paths are pruned and paths reinstalled at the new maximum number. During this route-reduction period, you may experience some packet loss for a few seconds. This may impact route traffic.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to allow a maximum of two paths to a destination:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# maximum paths 2
To limit the aggregate number of prefixes that can be redistributed into an Open Shortest Path First (OSPF) process, use the maximum redistributed-prefix command in the appropriate mode. To return to the default limit, use the no form of this command.
maximum redistributed-prefixes maximum [threshold-value] [warning-only]
no maximum redistributed-prefixes
maximum |
Number of routes. Range is 1 to 4294967295. |
threshold-value |
(Optional) Threshold value (as a percentage) at which to generate a warning message. Range is 1 to 100. |
warning-only |
(Optional) Gives only a warning when the limit is exceeded. |
If the command is not specified, the default is 10000.
The threshold value defaults to 75 percent.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the maximum redistributed-prefixes command to increase or decrease the maximum number of prefixes (also referred to as routes) redistributed for an OSPF process.
If the maximum value is less than the existing number of routes, existing routes remain configured, but no new routes are redistributed.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure a maximum number of routes that can be redistributed for an OSPF routing process:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# maximum redistributed-prefixes 15000
Command |
Description |
---|---|
Displays the OSPF topology table. |
To specify a key used with Open Shortest Path First (OSPF) Message Digest 5 (MD5) authentication, use the message-digest-key command in the appropriate mode. To remove an old MD5 key, use the no form of this command.
message-digest-key key-id md5 { key | clear key | encrypted key }
no message-digest-key key-id
key-id |
Key number. Range is 1 to 255. |
md5 |
Enables OSPF MD5 authentication. |
key |
Alphanumeric string of up to 16 characters. |
clear |
Specifies that the key be clear text. |
encrypted |
Specifies that the key be encrypted using a two-way algorithm. |
If this command is not specified in interface configuration mode, then the interface adopts the message digest key parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the message digest key parameter specified for the process.
If this command is not specified at any level, then OSPF MD5 authentication is disabled.
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Usually, one key individual interface is used to generate authentication information when packets are sent and to authenticate incoming packets. The same key identifier on the neighbor router must have the same key value.
For authentication to be enabled, you must configure the message-digest-key command together with the authentication command and its message-digest keyword. Both the message-digest-key and authentication commands can be inherited from a higher configuration level.
The process of changing keys is as follows. Suppose the current configuration is:
interface GigabitEthernet 0/3/0/2 message-digest-key 100 md5 OLD
You change the configuration to the following:
interface GigabitEthernet 0/3/0/2 message-digest-key 101 md5 NEW
The system assumes its neighbors do not have the new key yet, so it begins a rollover process. It sends multiple copies of the same packet, each authenticated by different keys. In this example, the system sends out two copies of the same packet—the first one authenticated by key 100 and the second one authenticated by key 101.
Rollover allows neighboring routers to continue communication while the network administrator is updating them with the new key. Rollover stops after the local system finds that all its neighbors know the new key. The system detects that a neighbor has the new key when it receives packets from the neighbor authenticated by the new key.
After all neighbors have been updated with the new key, the old key should be removed. In this example, you would enter the following:
interface ethernet 1 no ospf message-digest-key 100
Then, only key 101 is used for authentication on interface 1.
We recommend that you not keep more than one key individual interface. Every time you add a new key, you should remove the old key to prevent the local system from continuing to communicate with a hostile system that knows the old key. Removing the old key also reduces overhead during rollover.
Note | The MD5 key is always stored in encrypted format on the router. The clear and encrypted keywords inform the router whether the value that is entered is encrypted or unencrypted. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set a new key 19 with the password 8ry4222 :
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# message-digest-key 19 md5 8ry4222
Command |
Description |
---|---|
Configures an OSPF area. |
|
Enables plain text, MD5 authentication, or null authentication for an OSPF interface. |
|
Enables authentication for an OSPF area. |
To enable Label Distribution Protocol (LDP)-Interior Gateway Protocol (IGP) interface automatic configuration, use the mpls ldp auto-config command in the appropriate mode. To disable LDP-IGP interface automatic configuration, use the no form of this command.
mpls ldp auto-config
no mpls ldp auto-config
LDP-IGP interface automatic configuration is disabled for OSPF.
Interface configuration
Area configuration
Router configuration
Release |
Modification |
---|---|
Release 3.6.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable LDP-IGP interface automatic configuration:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf o1 RP/0/0/CPU0:router(config-ospf)# mpls ldp auto-config
To enable Label Distribution Protocol (LDP)-Interior Gateway Protocol (IGP) synchronization, use the mpls ldp sync command in the appropriate mode. To disable LDP-IGP synchronization, use the no form of this command.
mpls ldp sync [disable]
no mpls ldp sync
disable |
(Optional) Disables MPLS LDP synchronization from within the OSPF interface and area configuration submodes only. For the OSPF router configuration mode, use the no form of the command. |
LDP-IGP synchronization is disabled for OSPF.
Interface configuration
Area configuration
Router configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable LDP-IGP synchronization:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf o1 RP/0/0/CPU0:router(config-ospf)# mpls ldp sync
To configure and enable Label Distribution Protocol- Interior Gateway Protocol (LDP-IGP) synchronization on Multiprotocol Label Switching (MPLS) shortcuts (auto-route announced tunnels) only, use the mpls ldp sync-igp-shortcuts command in the appropriate OSPF configuration mode. To disable the use of LDP-IGP synchronization on MPLS shortcuts, use the no form of this command.
mpls ldp sync-igp-shortcuts [disable]
no mpls ldp sync-igp-shortcuts
disable |
(Optional) Disables MPLS LDP synchronization with IGP shortcuts from within the OSPF interface and area configuration submodes only. For the OSPF router configuration mode, use the no form of the command. |
LDP-IGP synchronization is disabled on MPLS tunnels.
OSPF interface configuration
OSPF router configuration
OSPF area configuration
Release |
Modification |
---|---|
Release 3.5.4 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When mpls ldp sync-igp-shortcuts is configured at a higher mode (area or instance level), you can selectively disable LDP-IGP synchronization on specific interfaces or areas by using the disable form of the command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable LDP-IGP synchronization shortcuts under OSPF interface configuration, using the mpls ldp sync-igp-shortcuts command on a tunnel-te interface. However, the command applies to all interfaces under the applicable configuration mode.
RP/0/0/CPU0:router(config)# router ospf 100 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface tunnel-te 1 RP/0/0/CPU0:router(config-ospf-ar-if)# mpls ldp sync-igp-shortcuts
When mpls ldp sync-igp-shortcuts is configured at a higher mode (area or instance level), you can selectively disable LDP-IGP synchronization on specific interfaces or areas by using the disable form of the command:
The following example shows how to enable the use of LDP-IGP synchronization across all interfaces in all areas except area 10:
RP/0/0/CPU0:router(config)# router ospf foo RP/0/0/CPU0:router(config-ospf)# mpls ldp sync-igp-shortcuts RP/0/0/CPU0:router(config-ospf)# area 10 RP/0/0/CPU0:router(config-ospf-ar)# mpls ldp sync-igp-shortcuts disable
Command |
Description |
---|---|
Enables Label Distribution Protocol (LDP)-Interior Gateway Protocol (IGP) synchronization. |
To configure an Open Shortest Path First (OSPF) area for Multiprotocol Label Switching traffic engineering (MPLS TE), use the mpls traffic-eng command in the appropriate configuration mode. To remove the MPLS TE from an area, use the no form of this command.
mpls traffic-eng
no mpls traffic-eng
This command has no keywords or arguments.
MPLS TE is not configured for OSPF.
Area configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.0 |
The area area-id keyword and argument pair was removed. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You must configure the mpls traffic-eng command for OSPF to support MPLS traffic engineering. OSPF provides the flooding mechanism that is used to flood TE link information.
Note | This command is supported only in the default VRF mode. |
We recommend that you configure the mpls traffic-eng router-id command instead of using the router-id command in global configuration mode.
OSPF support for MPLS TE is a component of the overall MPLS TE feature. Other MPLS TE software components must also be configured for this feature to be fully supported.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to associate loopback interface 0 with area 0, and area 0 is declared to be an MPLS area:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# router-id 10.10.10.10 RP/0/0/CPU0:router(config-ospf)# mpls traffic-eng router-id loopback 0 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf)# mpls traffic-eng RP/0/0/CPU0:router(config-ospf-ar)# interface loopback 0
Command |
Description |
---|---|
Controls the OSPF opaque LSA support capability. |
|
Specifies that the traffic engineering router identifier for the node is the IP address associated with a given interface. |
|
Configures a router ID for the OSPF process. |
To ensure that the OSPF protocol installs at least one IPv4 next-hop when it adds the tunnel next-hops (igp-shortcuts), use the mpls traffic-eng igp-intact command in the router configuration mode. To disable IGP-intact, use the no form of this command.
mpls traffic-eng igp-intact
no mpls traffic-eng igp-intact
IGP-intact is disabled.
Router configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The OSPF protocol adds both tunnel next-hops (igp-shortcuts) and IPv4 next-hops to the next-hop list in the Routing Information Base (RIB), until it reaches the maximum number of paths. When IGP-intact is enabled, it ensures that the Routing Information Base (RIB) always has at least one IPv4 next-hop present in the list of next-hops when the number of paths is at maximum.
Note | IGP-intact should be used only when Policy-Based Tunnel Selection (PBTS) is in use. |
Configure IGP-intact only when Policy-Based Tunnel Selection (PBTS) is in use. This ensures that at least one IPv4 next-hop is available for the default Differentiated Services Code Point (DSCP) traffic class. It also prevents traffic loss for other DSCP traffic classes by diverting such traffic to an IPv4 next-hop when the corresponding tunnel is unavailable for forwarding.
When Policy-Based Tunnel Selection (PBTS) is in use, traffic that is not policy-based is forwarded to an IGP path that may not have fast reroute (FRR) protection. Configuring IGP-intact when PBTS is not in use, causes traffic to be forwarded indiscriminately to an IGP path that may not have FRR protection.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable IGP-intact:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# mpls traffic-eng igp-intact
Command |
Description |
---|---|
Configures the maximum number of parallel routes that the Open Shortest Path First (OSPF) protocol can support. |
To enable multicast-intact for Open Shortest Path First (OSPF) routes so that multicast-intact paths are published to the Routing Information Base (RIB), use the mpls traffic-eng multicast-intact command in the appropriate configuration mode. To remove the MPLS TE area, use the no form of this command.
mpls traffic-eng multicast-intact
no mpls traffic-eng multicast-intact
This command has no keywords or arguments.
MPLS TE is not configured for OSPF.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
OSPF support for MPLS TE is a component of the overall MPLS TE feature. Other MPLS TE software components must also be configured for this feature to be fully supported.
Note | This command is supported only in the default VRF mode. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable publishing of multicast-intact paths to RIB:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# mpls traffic-eng multicast-intact
To enable Label Distribution Protocol (LDP)-OSPF Type 1 and Type 10 link-state advertisement (LSA) synchronization, use the mpls traffic-eng ldp-sync-update command in the appropriate mode. To disable LDP-LSA synchronization, use the no form of this command.
mpls traffic-eng ldp-sync-update
no mpls traffic-eng ldp-sync-update
LDP-LSA synchronization is disabled for OSPF.
Router configuration
Interface configuration
Area configuration
Release |
Modification |
---|---|
Release 4.2.4 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Whenever there is a change in the network (link failure, addition, new nodes, cost change or router cost out), the Type 1 and Type 10 LSA should be in sync. In most of the cases Type 1 and Type 10 are in sync, however it was observed that when IGP-LDP sync is not established, the Type 1 indicates the high cost while the Type 10 shows the normal cost. Use the mpls traffic-eng ldp-sync-update command to synchronize Label Distribution Protocol (LDP)-OSPF Type 1 and Type 10 link-state advertisement (LSA).
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable LDP-IGP OSPF Type 1 and Type 10 link-state advertisement (LSA) synchronization:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf o1 RP/0/0/CPU0:router(config-ospf)# mpls traffic-eng ldp-sync-update
To specify that the traffic engineering router identifier for the node is the IP address associated with a given Open Shortest Path First (OSPF) interface, use the mpls traffic-eng router-id command in the appropriate configuration mode. To disable this feature, use the no form of this command.
mpls traffic-eng router-id { router-id | type interface-path-id }
no mpls traffic-eng router-id { router-id | type interface-path-id }
router-id |
The 32-bit router ID value specified in four-part, dotted-decimal notation (must be in the valid IP address range of 0.0.0.0 to 255.255.255.255). |
type |
Interface type. For more information, use the question mark (?) online help function. |
interface-path-id |
Physical interface or virtual interface. Use the show interfaces command to see a list of all interfaces currently configured on the router. For more information about the syntax for the router, use the question mark (?) online help function. |
If this command is specified in router configuration mode, then the traffic engineering router identifier for the node is the IP address associated with a given interface.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This identifier of the router acts as a stable IP address for the traffic engineering configuration. This IP address is flooded to all nodes. For all traffic engineering tunnels originating at other nodes and ending at this node, you must set the tunnel destination to the traffic engineering router identifier of the destination node, because that is the address that the traffic engineering topology database at the tunnel head uses for its path calculation.
Note | We recommend that loopback interfaces be used for Multiprotocol Label Switching traffic engineering (MPLS TE), because they are more stable than physical interfaces. |
Note | This command is supported only in the default VRF mode. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to specify the traffic engineering router identifier as the IP address associated with loopback interface 0:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# mpls traffic-eng router-id loopback 0
Command |
Description |
---|---|
Configures an OSPF area for MPLS TE. |
To prevent Open Shortest Path First (OSPF) from checking whether neighbors are using the same maximum transmission unit (MTU) on a common interface when exchanging database descriptor (DBD) packets, use the mtu-ignore command in the appropriate mode. To reset to default, use the no form of this command.
mtu-ignore [ disable | enable ]
no mtu-ignore
disable |
(Optional) Enables checking for whether OSPF neighbors are using the MTU on a common interface. |
enable |
(Optional) Disables checking for whether OSPF neighbors are using the MTU on a common interface. |
The default is mtu-ignore with no keywords, which disables MTU checking.
If this command is not specified in interface configuration mode,
then the interface adopts the MTU ignore parameter specified by the area.
If this command is not specified in area configuration mode,
then the interface adopts the MTU ignore parameter specified for the process.
If this command is not specified at any level,
then OSPF checks the MTU received from neighbors when exchanging DBD packets.
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
OSPF checks whether OSPF neighbors are using the same MTU on a common interface. This check is performed when neighbors exchange DBD packets. If the receiving MTU in the DBD packet is higher than the MTU configured on the incoming interface, OSPF adjacency is not established.
The keywords, disable and enable , do not need to be used. If no keywords are used, the mtu-ignore command disables MTU checking. You can then use the no mtu-ignore command to activate MTU checking.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to disable MTU mismatch detection on receiving DBD packets:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# mtu-ignore
To enable multiple adjacencies for different Open Shortest Path First (OSPF) areas and enter multi-area interface configuration mode, use the multi-area-interface command in the area configuration mode. To reset to the default, use the no form of this command.
multi-area-interface type interface-path-id
no multi-area-interface type interface-path-id
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
An OSPF network is enabled for one area only.
Area configuration
Release |
Modification |
---|---|
Release 3.4.1 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the multi-area-interface command to enable area border routers (ABRs) to establish multiple adjacencies for different OSPF areas.
Each multiple area adjacency is announced as a point-to-point unnumbered link in the configured area. This point-to-point link provides a topological path for that area. The first or primary adjacency using the link advertises the link consistent with draft-ietf-ospf-multi-area-adj-06.txt.
You can configure multi-area adjacency on any interface where only two OSF speakers are attached. In the case of native broadcast networks, the interface must be configured as an OPSF point-to-point type using the network point-to-point command to enable the interface for a multi-area adjacency.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to enable multiple area adjacency for OSPF 109:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# area 1 RP/0/0/CPU0:router(config-ospf-ar)# multi-area-interface GigabitEthernet 0/1/0/3 RP/0/0/CPU0:router(config-ospf-ar-mif)# ? authentication Enable authentication authentication-key Authentication password (key) commit Commit the configuration changes to running cost Interface cost database-filter Filter OSPF LSA during synchronization and flooding dead-interval Interval after which a neighbor is declared dead describe Describe a command without taking real actions distribute-list Filter networks in routing updates do Run an exec command exit Exit from this submode hello-interval Time between HELLO packets message-digest-key Message digest authentication password (key) mtu-ignore Enable/Disable ignoring of MTU in DBD packets no Negate a command or set its defaults packet-size Customize size of OSPF packets upto MTU pwd Commands used to reach current submode retransmit-interval Time between retransmitting lost link state advertisements root Exit to the global configuration mode show Show contents of configuration transmit-delay Estimated time needed to send link-state update packet RP/0/0/CPU0:router(config-ospf-ar-mif)#
Command |
Description |
---|---|
Displays OSPF interface information. |
To configure Open Shortest Path First (OSPF) routers interconnecting to nonbroadcast networks, use the neighbor command in interface configuration mode. To remove a configuration, use the no form of this command.
neighbor ip-address [ cost number ] [ priority number ] [ poll-interval seconds ]
no neighbor ip-address [ cost number ] [ priority number ] [ poll-interval seconds ]
ip-address |
Interface IP address of the neighbor. |
cost number |
(Optional) Assigns a cost to the neighbor, in the form of an integer from 1 to 65535. Neighbors with no specific cost configured assume the cost of the interface, based on the cost command. On point-to-multipoint interfaces, cost number is the only keyword and argument combination that works. The cost keyword does not apply to nonbroadcast multiaccess (NBMA) networks. |
priority number |
(Optional) Specifies an 8-bit number indicating the router priority value of the nonbroadcast neighbor associated with the IP address specified. The priority keyword does not apply to point-to-multipoint interfaces. |
poll-interval seconds |
(Optional) Specifies an unsigned integer value (in seconds) reflecting the poll interval. RFC 1247 recommends that this value be much larger than the hello interval. The poll-interval keyword does not apply to point-to-multipoint interfaces. |
No configuration is specified.
priority number : 0
poll-interval seconds : 120 seconds (2 minutes)
Interface configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You must include one neighbor entry in the software configuration for each known nonbroadcast network neighbor. The neighbor address must be on the primary address of the interface.
If a neighboring router has become inactive (hello packets have not been received for the router dead interval period), it may still be necessary to send hello packets to the dead neighbor. These hello packets are sent at a reduced rate called the poll interval.
When the router starts up, it sends only hello packets to those routers with nonzero priority; that is, routers that are eligible to become designated routers (DRs) and backup designated routers (BDRs). After the DR and BDR are selected, the DR and BDR start sending hello packets to all neighbors to form adjacencies.
To filter all outgoing OSPF link-state advertisement (LSA) packets for the neighbor, use the neighbor database-filter all out command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to declare a router at address 172.16.3.4 on a nonbroadcast network, with a priority of 1 and a poll interval of 180 seconds:
RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.4 priority 1 poll-interval 180
The following example illustrates a network with nonbroadcast:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface GigabitEthernet1/0/0/3 RP/0/0/CPU0:router(config-if)# ip address 172.16.3.10 255.255.255.0 RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet1/0/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# network nonbroadcast RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.4 priority 1 poll-interval 180 RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.5 cost 10 priority 1 poll-interval 180 RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.6 cost 15 priority 1 poll-interval 180 RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.7 priority 1 poll-interval 180
Command |
Description |
---|---|
Filters all outgoing LSAs to an OSPF neighbor. |
|
Configures the OSPF network type to a type other than the default for a given medium. |
|
Sets the router priority, which helps determine the designated router for this network. |
To filter all outgoing link-state advertisements (LSAs) to an Open Shortest Path First (OSPF) neighbor, use the neighbor database-filter all out command in interface configuration mode. To restore the forwarding of LSAs to the neighbor, use the no form of this command.
neighbor ip-address database-filter all out
no neighbor ip-address database-filter all out
ip-address |
IP address of the neighbor to which outgoing LSAs are blocked. |
Instead of all outgoing LSAs being filtered to the neighbor, they are flooded to the neighbor.
Interface configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the neighbor database-filter all out command to filter all outgoing OSPF LSA packets during synchronization and flooding for point-to-multipoint neighbors on nonbroadcast networks. More neighbor options are available with the neighbor command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to prevent flooding of OSPF LSAs from point-to-multipoint networks to the neighbor at IP address 10.2.3.4:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet1/0/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 10.2.3.4 database-filter all out
Command |
Description |
---|---|
Configures OSPF routers interconnecting to nonbroadcast networks. |
To configure the Open Shortest Path First (OSPF) network type to a type other than the default for a given medium, use the network command in the appropriate mode. To return to the default value, use the no form of this command.
network { broadcast | non-broadcast | { point-to-multipoint [non-broadcast] | point-to-point } }
no network
broadcast |
Sets the network type to broadcast. |
non-broadcast |
Sets the network type to nonbroadcast multiaccess (NBMA). |
point-to-multipoint |
Sets the network type to point-to-multipoint. |
non-broadcast |
(Optional) Sets the point-to-multipoint network to be nonbroadcast. If you use this keyword, the neighbor command is required. |
point-to-point |
Sets the network type to point-to-point. |
If this command is not specified in interface configuration mode, then the interface adopts the network parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the network parameter specified for the process.
If this command is not specified at any level, then the OSPF network type is the default of the given medium.
POS interfaces default to point-to-point and GigabitEthernt and TenGigEthernet interfaces default to broadcast.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the network command to configure broadcast networks as NBMA networks when, for example, routers in your network do not support multicast addressing.
Configuring NBMA networks as either broadcast or nonbroadcast assumes that there are virtual circuits from every router to every router or fully meshed network. However, there are other configurations where this assumption is not true; for example, a partially meshed network. In these cases, you can configure the OSPF network type as a point-to-multipoint network. Routing between two routers that are not directly connected go through the router that has virtual circuits to both routers. You need not configure neighbors when using this command.
If this command is issued on an interface that does not allow it, this command is ignored.
OSPF has two features related to point-to-multipoint networks. One feature applies to broadcast networks; the other feature applies to nonbroadcast networks:
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the OSPF network as a nonbroadcast network:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# router ospf 1 RP/0/RP0/CPU0:router(config-ospf)# area 0 RP/0/RP0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3 RP/0/RP0/CPU0:router(config-ospf-ar-if)# network non-broadcast RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.4 priority 1 poll-interval 180
Command |
Description |
---|---|
Configures OSPF routers interconnecting to nonbroadcast networks. |
To configure nonstop forwarding (NSF) for the Open Shortest Path First (OSPF) protocol, use the nsf command in the appropriate mode. To remove this command from the configuration file and restore the system to its default condition, use the no form of this command.
nsf { cisco [ enforce global ] | ietf [ helper disable ] }
no nsf { cisco [ enforce global ] | ietf [ helper disable ] }
cisco |
Enables Cisco Nonstop Forwarding. |
enforce global |
(Optional) Cancels NSF restart when non-NSF network device neighbors are detected. |
ietf |
Enables Internet Engineering Task Force (IETF) graceful restart. |
helper disable |
(Optional) Disables router helper support. |
NSF is disabled.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The NSF feature allows for the forwarding of data packets to continue along known routes while routing protocol information (such as OSPF) is being restored following a switchover.
Use the nsf command if the router is expected to perform NSF during restart. To experience the full benefits of this feature, configure all neighboring routers with NSF.
When this command is used without the optional cisco enforce global keywords and non-NSF neighbors are detected, the NSF restart mechanism aborts on the interfaces of those neighbors and functions properly on others.
When this command is used with the optional cisco enforce global keywords and non-NSF neighbors are detected, NSF restart is canceled for the entire OSPF process.
IETF graceful restart provides an NSF mechanism to allow data traffic to flow seamlessly with no packet drops during the transient period when OSPF attempts to recover after a process restart or RP failover, within the guidelines of RFC 3623.
By default, neighbors in helper mode listen to both the NSF Cisco- and NSF IETF-type LSAs. The nsf command enables one type of mechanism that would undergo an RP failover or, anticipating an OSPF process restart. If the cisco or ietf keyword is not entered, NSF is not enabled, irrespective of neighbors in listening mode for both NSF Cisco and NSF IETF.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to cancel NSF restart for the entire OSPF process if non-NSF neighbors are detected on any network interface during restart:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# nsf cisco enforce global
To configure the maximum time allowed for nonstop forwarding (NSF) external route queries for the Open Shortest Path First (OSPF) protocol, use the nsf flush-delay-time command in the appropriate mode. To remove this command from the configuration file and restore the system to its default condition, use the no form of this command.
nsf flush-delay-time seconds
no nsf flush-delay-time seconds
seconds |
Length of time (in seconds) allowed for NSF external route queries. Range is 1 to 3600 seconds. |
seconds : 300
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the maximum time for NSF to learn external routes for OSPF at 60 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# nsf flush-delay-time 60
To configure the minimum time between consecutive nonstop forwarding (NSF) restart attempts for the Open Shortest Path First (OSPF) protocol, use the nsf interval command in the appropriate mode. To remove this command from the configuration file and restore the system to its default condition, use the no form of this command.
nsf interval seconds
no nsf interval seconds
seconds |
Length of time (in seconds) between consecutive restart attempts. Range is 90 to 3600 seconds. |
seconds : 90
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.6.0 |
Minimum number for the seconds argument was changed from 95 to 90. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When you use the nsf interval command, the OSPF process must be up for at least 90 seconds before OSPF attempts to perform an NSF restart.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the minimum time between consecutive NSF restart attempts at 120 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:routerr(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# nsf interval 120
To configure the maximum time that routes are held in the Routing Information Base (RIB) following an Open Shortest Path First (OSPF) process restart, use the nsf lifetime command in the appropriate mode. To remove this command from the configuration file and restore the system to its default condition, use the no form of this command.
nsf lifetime seconds
no nsf lifetime seconds
seconds |
The length of time (in seconds) that routes are held in the RIB. Range is 90 to 3600 seconds. |
seconds : 95
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When you use this command, the OSPF process must reconverge within the maximum length of time configured. If the convergence exceeds this length of time, routes are purged from RIB and nonstop forwarding (NSF) restart may fail.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the maximum lifetime for OSPF NSF at 120 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# nsf lifetime 120
To configure an area as a not-so-stubby area (NSSA), use the nssa command in area configuration mode. To remove the NSSA distinction from the area, use the no form of this command.
nssa [no-redistribution] [ default-information-originate [ metric metric-value ] [ metric-type type-value ] ] [no-summary]
no nssa
no-redistribution |
(Optional) Imports routes only into the normal areas, but not into the NSSA area, by the redistribute command when the router is an NSSA Area Border Router (ABR). |
default-information- originate |
(Optional) Generates a Type 7 default into the NSSA area. This keyword takes effect only on an NSSA ABR or NSSA Autonomous System Boundary Router (ASBR). |
metric metric-value |
(Optional) Specifies the metric used for generating the default route. If you omit a value and do not specify a value using the defaultmetric command, the default metric value is 10. Range is 1 to 16777214. |
metric-type type-value |
(Optional) Specifies the external link type associated with the default route advertised into the OSPF routing domain. It can be one of the following values: 1—Type 1 external route 2—Type 2 external route |
no-summary |
(Optional) Prevents an ABR from sending summary link advertisements into the NSSA. |
No NSSA area is defined.
Area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
Added metric and metric-type keywords. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
An NSSA does not flood Type 5 external LSAs from the core into the area, but can import autonomous system external routes in a limited fashion within the area.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure area 1 as an NSSA area:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 1 RP/0/0/CPU0:router(config-ospf-ar)# nssa
To configure the Open Shortest Path First (OSPF) protocol to look up Domain Name System (DNS) names, use the ospf name-lookup command in global configuration mode. To disable this function, use the no form of this command.
ospf name-lookup
no ospf name-lookup
Routers are displayed by router ID or neighbor ID.
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the ospf name-lookup command to easily identify a router when executing all OSPF show command displays. The router is displayed by name rather than by its router ID or neighbor ID.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure OSPF to identify a router by name:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# ospf name-lookup
To configure the size of Open Shortest Path First (OSPF) packets up to the size specified by the maximum transmission unit (MTU), use the packet-size command in the appropriate configuration mode. To disable this function and reestablish the default packet size, use the no form of this command.
packet-size bytes
no packet-size
bytes |
Size, in bytes. Range is 576 to 10000 bytes. |
If the command is not specified, the default packet size is either the interface IP MTU size (if that is lower than 9000 bytes) or 9000 bytes.
Router configuration
Area configuration
Interface configuration
VRF configuration
Multi-area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.9.0 |
The default packet size was changed to minimum of the interface IP MTU size or 9000 bytes. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the packet-size command to customize the size of OSPF packets. The OSPF protocol compares the packet size and the MTU size and uses the lower packet size value.
If the command is not configured, the default packet size is equal to the interface IP MTU size (if that is lower than 9000 bytes) or 9000 bytes. For example, if the interface IP MTU size is 1500 bytes, OSPF uses packet size of 1500 bytes on the interface because the byte size is lower than 9000 bytes. If the interface IP MTU size is 9500 bytes, OSPF uses packet size of 9000 bytes on the interface because the byte size exceeds 9000 bytes. The interface IP MTU size depends on the interface and the platform. In most cases, the default interface IP MTU value will be lower than 9000 bytes.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure the packet size on an interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 1/0/0/2 RP/0/0/CPU0:router(config-ospf-ar-if)# packet-size 3500
To suppress the sending of Open Shortest Path First (OSPF) protocol operation on an interface, use the passive command in the appropriate mode. To remove the passive configuration, use the no form of this command.
passive [ disable | enable ]
no passive
disable |
(Optional) Sends OSPF updates. |
enable |
(Optional) Disables sending OSPF updates. |
If this command is not specified in interface configuration mode, then the interface adopts the passive parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the passive parameter specified for the process.
If this command is not specified at any level, then the passive parameter is disabled and OSPF updates are sent on the interface.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.6.0 |
The enable keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
OSPF routing information is neither sent nor received through the specified interface. The interface appears as a stub network in the OSPF router (Type 1) link-state advertisement (LSA).
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows that GigabitEthernet interface 1/0/0/2 reduces OSPF updates because passive mode is enabled; however, GigabitEthernet interface 0/1/0/3 receives normal OSPF traffic flow:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet1/0/0/2 RP/0/0/CPU0:router(config-ospf-ar-if)# passive RP/0/0/CPU0:router(config-ospf-ar-if)# exit RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet1/0/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# end
To set the router priority for an interface, which helps determine the designated router for an Open Shortest Path First (OSPF) link, use the priority command in the appropriate mode. To return to the default value, use the no form of this command.
priority value
no priority value
value |
8-bit unsigned integer indicating the router priority value. Range is 0 to 255. |
If this command is not specified in interface configuration mode, then the interface adopts the priority parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the priority parameter specified for the process.
If this command is not specified at any level, then the default priority is 1.
Interface configuration
Area configuration
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When two routers attached to a network both attempt to become the designated router, the one with the higher router priority takes precedence. If there is a tie, the router with the higher router ID takes precedence. A router with a router priority set to zero is ineligible to become the designated router or backup designated router. Router priority is configured only for interfaces to multiaccess networks (in other words, not point-to-point networks).
This priority value is used when you configure the Open Shortest Path First (OSPF) protocol for nonbroadcast networks using the neighbor command for OSPF.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows that priority is set through the priority and neighbor commands for Routers A and B and that the neighbor priority value must reflect that of the neighbor router:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-if)# ipv4 address 10.0.0.2 255.255.255.0 RP/0/0/CPU0:router(config-if)# exit RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# network non-broadcast RP/0/0/CPU0:router(config-ospf-ar-if)# priority 4 RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 10.0.0.1 priority 6
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface GigabitEthernet POS 0/2/0/1 RP/0/0/CPU0:router(config-if)# ipv4 address 10.0.0.1 255.255.255.0 RP/0/0/CPU0:router(config-if)# exit RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/2/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# network non-broadcast RP/0/0/CPU0:router(config-ospf-ar-if)# priority 6 RP/0/0/CPU0:router(config-ospf-ar-if)# neighbor 10.0.0.2 priority 4
Command |
Description |
---|---|
Configures OSPF routers interconnecting to nonbroadcast networks. |
|
Configures the OSPF network type to a type other than the default for a given medium. |
To disable an instance of the Open Shortest Path First (OSPF) protocol so that it cannot form an adjacency on any interface, use the protocol shutdown command in the router configuration mode. To reenable the OSPF protocol, use the no form of this command.
protocol shutdown
no protocol shutdown
No default behavior or values
Router configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the protocol shutdown command to disable the OSPF protocol for a specific routing instance without removing any existing OSPF configuration parameters.
The OSPF protocol continues to run on the router and you can use the current OSPF configuration, but OSPF does not form any adjacencies on any interface.
This command is similar to performing the no router ospf command.
Task ID |
Operations |
---|---|
ospf |
read, write |
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospfv3 1 RP/0/0/CPU0:router(config-ospf)# protocol shutdown
To change the number of LSAs scheduled (rate-limited) for flushing, that are processed in each iteration, use the queue dispatch flush-lsa command in router configuration mode. To return to the system default value, use the no form of this command.
queue dispatch flush-lsa count
no queue dispatch flush-lsa
count |
Maximum number of LSAs flushed per run. Range is 30 to 3000. |
The default LSAs flushed per run is 150 (when the count is not configured).
Router configuration
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to limit the number of LSAs flushed per run to 30:
RP/0/0/CPU0:router(config-ospf)# queue dispatch flush-lsa 30
Use the show ospf message-queue command to see the queue dispatch values, peak lengths, and limits.
Command |
Description |
---|---|
Limits the number of continuous incoming events processed. |
|
Sets the maximum number of rate-limited link-state advertisements (LSAs) processed per run. |
|
Limits the number of summary or external Type 3 to Type 7 link-state advertisements (LSAs) processed per shortest path first (SPF) run. |
|
Sets the high watermark for incoming priority events. |
|
Displays the information about the queue dispatch values, peak lengths, and limits. |
To limit the number of incoming packets (LSAUpdates, LSAcks, DBDs, LSRequests, and Hellos that trigger a change state) processed, use the queue dispatch incoming command in router configuration mode. To return to the system default value, use the no form of this command.
queue dispatch incoming count
no queue dispatch incoming
count |
Maximum number of continuous events processed. Range is 30 to 3000. |
The default incoming count is 300 packets (when the count is not configured).
Router configuration
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how limit the number of incoming packets processed to 500:
RP/0/0/CPU0:router(config-ospf)# queue dispatch incoming 500
Use the show ospf message-queue command to see the queue dispatch values, peak lengths, and limits.
Command |
Description |
---|---|
Sets the maximum number of rate-limited link-state advertisements (LSAs) processed per run. |
|
Limits the number of summary or external Type 3 to Type 7 link-state advertisements (LSAs) processed per shortest path first (SPF) run. |
|
Sets the high watermark for incoming priority events. |
|
Displays the information about the queue dispatch values, peak lengths, and limits. |
To set the maximum number of rate-limited link-state advertisement (LSA) (re-)originations processed per run, use the queue dispatch rate-limited-lsa command in router configuration mode. To return to the system default value, use the no form of this command.
queue dispatch rate-limited-lsa count
no queue dispatch rate-limited-lsa
count |
Maximum number of rate-limited LSAs processed per run. Range is 30 to 3000. |
The default number of rate-limited LSAs processed per run is 300 (when this count is not configured).
Router configuration
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the maximum number of rate-limited LSA (re-)originations processed per run to 300:
RP/0/0/CPU0:router(config-ospf)# queue dispatch rate-limited-lsa 300
Command |
Description |
---|---|
Limits the number of continuous incoming events processed. |
|
Limits the number of summary or external Type 3 to Type 7 link-state advertisements (LSAs) processed per shortest path first (SPF) run. |
|
Sets the high watermark for incoming priority events. |
|
Displays the information about the queue dispatch values, peak lengths, and limits. |
To change the maximum number of Type 3-4 and Type 5-7 link-state advertisements (LSAs) processed per shortest path first (SPF) iteration within a single SPF run, use the queue dispatch spf-lsa-limit command in router configuration mode. To return to the system default value, use the no form of this command.
queue dispatch spf-lsa-limit count
no queue dispatch spf-lsa-limit
count |
Maximum number of continuous Type 3-4 and Type 5-7 LSAs processed per SPF in each scheduled iteration within a single SPF run. Range is 30 to 3000. |
The default number of Type 3-4 and Type 5-7 processed per run is 150 LSAs (when this command is not configured).
Router configuration
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to limit the number of continuous Type 3-4 and Type 5-7 LSAs processed by SPF per scheduling run, to 100:
RP/0/0/CPU0:router(config-ospf)# queue dispatch spf-lsa-limit 100
Command |
Description |
---|---|
Limits the number of continuous incoming events processed. |
|
Sets the maximum number of rate-limited link-state advertisements (LSAs) processed per run |
|
Sets the high watermark for incoming priority events. |
|
Displays the information about the queue dispatch values, peak lengths, and limits. |
To set the high watermark for incoming events by priority, use the queue limit in router configuration mode. To return to the system default values, use the no form of this command.
queue limit { high | medium | low } count
no queue limit { high | medium | low }
high |
High watermark for incoming high-priority events (state-changing Hellos). |
medium |
High watermark for incoming medium-priority events (LSA ACK). |
low |
High watermark for incoming low-priority events (DBD/LSUpd/LSReq). |
count |
Maximum number of events per queue. Events are dropped when the priority queue size exceeds this value. Range is 1000 to 30000. |
High watermark: 9500 (when the corresponding configuration is not present).
Medium watermark: 9000 (when the corresponding configuration is not present).
Low watermark: 8000 (when the corresponding configuration is not present).
Router configuration
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Always keep the limits in the following order of priority:
Limit for High > Limit for Medium > Limit for Low
Task ID |
Operations |
---|---|
ospf |
read, write |
The following examples show how to set the maximum number of events per queue:
RP/0/0/CPU0:router(config-ospf)# queue limit high 11000 RP/0/0/CPU0:router(config-ospf)# queue limit medium 10000 RP/0/0/CPU0:router(config-ospf)# queue limit low 9000
Command |
Description |
---|---|
Limits the number of continuous incoming events processed. |
|
Sets the maximum number of rate-limited link-state advertisements (LSAs) processed per run. |
|
Limits the number of summary or external Type 3 to Type 7 link-state advertisements (LSAs) processed per shortest path first (SPF) run. |
|
Displays the information about the queue dispatch values, peak lengths, and limits. |
To consolidate and summarize routes at an area boundary, use the range command in area configuration mode. To disable this function, use the no form of this command.
range ip-address mask [ advertise | not-advertise ]
no range ip-address mask [ advertise | not-advertise ]
ip-address |
IP address in four-part, dotted-decimal notation. |
mask |
IP address mask. |
advertise |
(Optional) Sets the address range status to advertise and generates a Type 3 summary link-state advertisement (LSA). |
not-advertise |
(Optional) Sets the address range status to DoNotAdvertise. The Type 3 summary LSA is suppressed and the component networks remain hidden from other networks. |
When this command is not specified for Area Border Routers (ABRs), routes at an area boundary are not consolidated or summarized.
Advertise is the default.
Area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the range command only with Area Border Router (ABRs). Use the command to consolidate or summarize routes for an area. The result is that a single summary route is advertised to other areas by the ABR. Routing information is condensed at area boundaries. External to the area, a single route is advertised for each address range. This process is called route summarization .
Multiple range configurations specifying the range command can be configured. Thus, the OSPF protocol can summarize addresses for many different sets of address ranges.
The summarized route uses the maximum cost of the routes assumed in the range.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows area 36.0.0.0 consisting of interfaces whose IP addresses have “10.31.x.x” as the first two octets. The range command summarizes interfaces. Instead of advertising eight networks individually, the single route 10.31.0.0 255.255.0.0 is advertised:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet 0/3/0/2 ! RP/0/0/CPU0:router(config-ospf)# area 36.0.0.0 RP/0/0/CPU0:router(config-ospf-ar)# range 10.31.0.0 255.255.0.0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/1/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/1/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/1/0/2 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/1/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/2/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/2/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/2/0/2 RP/0/0/CPU0:router(config-ospf-ar-if)# interface GigabitEthernet0/2/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# end
Command |
Description |
---|---|
Creates aggregate addresses for routes being redistributed from another routing protocol into the OSPF protocol. |
To redistribute routes from one routing domain into Open Shortest Path First (OSPF), use the redistribute command in the appropriate mode. To remove the redistribute command from the configuration file and restore the system to its default condition in which the software does not redistribute routes, use the no form of this command.
redistribute bgp process-id [preserve-med] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute bgp process-id [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute connected [ instance instance-name ] [ instance IPCP ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute connected [ instance instance-name ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute dagr [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute dagr [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute eigrp process-id [ match { external [ 1 | 2 ] | internal } ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute eigrp process-id [ match { external [ 1 | 2 ] | internal } ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute isis process-id [ level-1 | level-2 | level-1-2 ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute isis process-id [ level-1 | level-2 | level-1-2 ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute ospf process-id [ match { external [ 1 | 2 ] | internal | nssa-external [ 1 | 2 ] } ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute ospf process-id [ match { external [ 1 | 2 ] | internal | nssa-external [ 1 | 2 ] } ] [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute rip [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute rip [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
redistribute static [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
no redistribute static [ metric metric-value ] [ metric-type { 1 | 2 } ] [ route-policy policy-name ] [ tag tag-value ]
Route redistribution is disabled.
metric metric-value: Default is 20 for routes from all protocols except BGP routes, for which the default is 1.
metric-type : Type 2 external route.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. The policy keyword was changed to route-policy . The eigrp and rip keywords were added. |
Release 3.6.0 |
The following keywords and arguments were added to the redistribute eigrp command: [ metric metric-value ] [ metric-type { 1 | 2 }] [ route-policy policy-name ] [ tag tag-value ]. The preserve-med keyword was added to the redistribute bgp command. |
Release 3.9.0 |
Asplain format for 4-byte Autonomous system numbers notation was supported. Support was added for redistribution from directed-attached gateway redundancy (DAGR). The keyword dagr was added. The instance keywrod and instance-name argument were added for connected routes |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Note | When redistributing routes (into OSPF) using both command keywords for setting or matching of attributes and a route policy, the routes are run through the route policy first, followed by the keyword matching and setting. |
Redistributed routing information should always be filtered by the policy policy-name keyword and argument. This filtering ensures that only those routes intended by the administrator are redistributed into OSPF.
For information about routing policies, see the Routing Policy Commands on the Cisco IOS XR Software Cisco IOS XR module of Cisco IOS XR Routing Command Reference for the Cisco XR 12000 Series Router.
Whenever you use the redistribute or default-information originate (OSPF) command to redistribute routes into an OSPF routing domain, the router automatically becomes an ASBR. However, an ASBR does not, by default, generate a default route into the OSPF routing domain.
When routes are redistributed between OSPF processes, no OSPF metrics are preserved.
When routes are redistributed into OSPF and no metric is specified with the metric keyword, OSPF uses 20 as the default metric for routes from all protocols except BGP routes, which get a metric of 1.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to cause BGP routes to be redistributed into an OSPF domain:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 110 RP/0/0/CPU0:router(config-ospf)# redistribute bgp 100
The following example shows how to redistribute the specified IS-IS process routes into an OSPF domain. The IS-IS routes are redistributed with a metric of 100.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# redistribute isis 108 metric 100
In the following example, network 10.0.0.0 appears as an external link-state advertisement (LSA) in OSPF 1:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface GigabitEthernet 0/1/0/1 RP/0/0/CPU0:router(config-if)# ip address 10.0.0.0 255.0.0.0 ! RP/0/0/CPU0:router(config)# interface GigabitEthernet 0/2/0/2 RP/0/0/CPU0:router(config)# ip address 10.99.0.0 255.0.0.0 ! RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# redistribute ospf 2 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/2/0/2 ! RP/0/0/CPU0:router(config)# router ospf 2 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/1/0/1
Command |
Description |
---|---|
Generates a default external route into an OSPF routing domain. |
To specify the time between link-state advertisement (LSA) retransmissions for adjacencies belonging to the Open Shortest Path First (OSPF) interface, use the retransmit-interval command in the appropriate mode. To return to the default value, use the no form of this command.
retransmit-interval seconds
no retransmit-interval
seconds |
Time (in seconds) between retransmissions. It must be greater than the expected round-trip delay between any two routers on the attached network. Range is 1 to 65535 seconds. |
If this command is not specified in interface configuration mode, then the interface adopts the retransmit interval parameter specified by the area.
If this command is not specified in area configuration mode, then the interface adopts the retransmit interval parameter specified for the process.
If this command is not specified at any level, then the default retransmit interval is 5 seconds.
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
This command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When a router sends an LSA to its neighbor, it keeps the LSA until it receives the acknowledgment message. If the router receives no acknowledgment, it resends the LSA.
The setting of this parameter should be conservative, or needless retransmission results. The value should be larger for serial lines and virtual links.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the retransmit interval value to 8 seconds in interface configuration mode:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/2/0/1 RP/0/0/CPU0:router(config-ospf-ar-if)# retransmit-interval 8
To specify a routing policy to filter Type 3 link-state advertisements (LSA), use the route-policy command in area configuration mode. To disable the routing policy, use the no form of this command.
route-policy route-policy-name { in | out }
no route-policy route-policy-name { in | out }
route-policy-name |
Name of route policy. |
in |
Applies policy to inbound routes. |
out |
Applies policy to outbound routes. |
No policy is applied.
Area configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the route-policy command to specify an OSPF routing policy for an inbound or outbound route. The policy can be used to filter routes or modify route attributes.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to specify an OSPF route policy for inbound routes in area 0:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-area)# route-policy area0_in in
To configure a router ID for the Open Shortest Path First (OSPF) process, use the router-id command in the appropriate mode. To cause the software to use the default method of determining the router ID, use the no form of this command after clearing or restarting the OSPF process.
router-id router-id
no router-id router-id
router-id |
32-bit router ID value specified in four-part, dotted-decimal notation. |
If this command is not configured, the router ID is the highest IP version 4 (IPv4) address for an interface on the router, with any loopback interface taking precedence.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.0 |
The type interface-path-id argument pair was removed. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
It is good practice to use the router-id command to explicitly specify a unique 32-bit numeric value for the router ID. This action ensures that OSPF can function regardless of the interface address configuration. Clear the OSPF process using the clear ospf process command or restart the OSPF process for the no router-id command to take effect.
OSPF attempts to obtain a router ID in the following ways (in order of preference):
By default, when the OSPF process initializes, it checks if there is a router-id in the checkpointing database.
The 32-bit numeric value specified by the OSPF router-id command in router configuration mode. (This value can be any 32-bit value. It is not restricted to the IPv4 addresses assigned to interfaces on this router, and need not be a routable IPv4 address.)
The ITAL selected router-id.
The primary IPv4 address of an interface over which this OSPF process is running. The first interface address in the OSPF interface is selected.
Note | Unlike OSPF version 3, OSPF version 2 is guaranteed to have at least one interface with an IPv4 address configured. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to assign the IP address of 172.20.10.10 to the OSPF process 109:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config-ospf)# router-id 172.20.10.10
Command |
Description |
---|---|
Resets an OSPF router process without stopping and restarting it. |
|
ipv4 address |
Sets a primary IPv4 address for an interface. |
To configure an Open Shortest Path First (OSPF) routing process, use the router ospf command in global configuration mode. To terminate an OSPF routing process, use the no form of this command.
router ospf process-name
no router ospf process-name
process-name |
Name that uniquely identifies an OSPF routing process. The process name is any alphanumeric string no longer than 40 characters without spaces. |
No OSPF routing process is defined.
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You can specify multiple OSPF routing processes in each router. Up to 10 processes can be configured. The recommendation is not to exceed 4 OSPF processes.
All OSPF configuration commands must be configured under an OSPF routing process. For example, two of these commands are the default-metric command and the router-id command.
Task ID |
Operations |
---|---|
ospf |
read, write |
rib |
read, write |
The following example shows how to instantiate an OSPF routing process called 109:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109
Command |
Description |
---|---|
Configures an OSPF area. |
|
Sets default metric values for routes redistributed from another protocol into the OSPF protocol. |
|
Defines the interfaces on which the OSPF protocol runs. |
|
Configures a router ID for the OSPF process. |
To set the security time-to-live (TTL) value in the IP header for Open Shortest Path First (OSPF) packets, use the security ttl command in the appropriate configuration mode. To remove this command from the configuration file and restore the system to its default condition, use the no form of this command.
security ttl [ hops hops-number ]
no security ttl
hops hops-number |
IP hops. Maximum number of hops allowed. Range is 1 to 254 hops. |
hops-number : 1
Router configuration
Area configuration
Interface configuration
Release |
Modification |
---|---|
Release 3.5.0 |
This command was introduced. |
Release 3.6.0 |
The disable keyword was removed. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The security ttl command is used for the Generalized TTL Security Mechanism (GTSM) feature to prevent network attacks.
During the act of receiving Link State Advertisement (LSA) from neighbors, network attacks can occur because there are no checks that unicast or multicast packets are originating from a neighbor that is one hop away or multiple hops away over virtual links.
For virtual links, OSPF packets travel multiple hops across the network; hence, the TTL value can be decremented several times. For these type of links, a minimum TTL value must be allowed and accepted for multiple-hop packets.
To filter network attacks originating from invalid sources traveling over multiple hops, the GTSM, RFC 3682, is used to prevent the attacks. GTSM filters link-local addresses and allows for only one-hop neighbor adjacencies through the configuration of TTL value 255. The TTL value in the IP header is set to when OSPF packets are originated and checked on the received OSPF packets against the default GTSM TTL value 255 or the user configured GTSM TTL value, blocking unauthorized OSPF packets originated from TTL hops away.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to set the security TTL for an interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet0/6/0/3 RP/0/0/CPU0:router(config-ospf-ar-if)# security ttl 2
To configure an Open Shortest Path First OSPF sham link between two provider edge routers, use the sham-link command in VRF area configuration mode. To terminate an (OSPF) sham link, use the no form of this command.
sham-link source-address destination-address
no sham-link
source-address |
IP address of the local (source) sham-link endpoint specified in four-part, dotted-decimal notation. |
destination-address |
IP address of the remote (destination) sham-link endpoint specified in four-part, dotted-decimal notation. |
No sham link is configured.
VRF area configuration.
Release |
Modification |
---|---|
Release 3.6.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the sham-link command to configure a point-to-point connection between two provider edge (PE) routers creating an interconnect between two VPN sites (VPN backbone). Sham links are configured on PE provider edge (PE) routers in a Multiprotocol Label Switching (MPLS) VPN backbone.
Task ID |
Operations |
---|---|
ospf |
read, write |
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 109 RP/0/0/CPU0:router(config_ospf)# vrf vrf_a RP/0/0/CPU0:router(config_ospf_vrf)# area 0 RP/0/0/CPU0:router(config_ospf_vrf_ar)# sham-link 192.168.40.0 172.16.30.0 RP/0/0/CPU0:router(config_ospf_vrf_ar_sl)# cost 23
Command |
Description |
---|---|
Configures an OSPF area. |
|
Explicitly specifies the cost of the interface (network) for OSPF path calculation. |
|
Configures an OSPF VPN routing and forwarding (VRF) instance. |
To display general information about Open Shortest Path First (OSPF) routing processes, use the show ospf command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [summary]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved values of the vrf-name argument. |
summary |
(Optional) Displays OSPF summary information. |
IPv4 and unicast address prefixes
EXEC
OSPFv3
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
Release 3.9.0 |
Asplain format for 4-byte Autonomous system numbers notation was supported. The input parameters and output were modified to display 4-byte autonomous system numbers and extended communities in either asplain or asdot notations. |
Release 4.3.0 |
The show ospf vrf vrf_name command output was modified to display the VRF lite configuration status. |
Release 5.1 |
The output of the command was modified to include OSPFv3 status. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf command to provide basic information about the OSPF processes running on the router. Additional options provide in-depth information.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf command:
RP/0/0/CPU0:router#show ospf
Routing Process "ospf 1" with ID 1.1.1.1
Supports only single TOS(TOS0) routes
Supports opaque LSA
It is an area border router
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Initial LSA throttle delay 500 msecs
Minimum hold time for LSA throttle 5000 msecs
Maximum wait time for LSA throttle 5000 msecs
Minimum LSA interval 5000 msecs. Minimum LSA arrival 1 secs
Maximum number of configured interfaces 255
Number of external LSA 0. Checksum Sum 00000000
Number of opaque AS LSA 0. Checksum Sum 00000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 2 normal 0 stub 0 nssa
External flood list length 0
Non-Stop Forwarding enabled
Area BACKBONE(0) (Inactive)
Number of interfaces in this area is 2
SPF algorithm executed 8 times
Number of LSA 2. Checksum Sum 0x01ba83
Number of opaque link LSA 0. Checksum Sum 00000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Area 1
Number of interfaces in this area is 1
SPF algorithm executed 9 times
Number of LSA 2. Checksum Sum 0x0153ea
Number of opaque link LSA 0. Checksum Sum 00000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Field |
Description |
---|---|
Routing Process “ospf 201” with ID 172.22.110.200 |
OSPF process name. |
Supports only |
Number of types of service supported (Type 0 only). |
It is |
Types are internal, area border, or autonomous system boundary. |
Redistributing External Routes from |
Lists of redistributed routes, by protocol. |
SPF schedule delay |
Delay time of SPF calculations. |
Minimum LSA interval |
Minimum interval between LSAs. |
Minimum LSA arrival |
Minimum elapsed time between accepting an update for the same link-state advertisement (LSA). |
external LSA |
Total number of Type 5 LSAs in the LSDB. |
opaque LSA |
Total number of Type 10 LSAs in the LSDB. |
DCbitless...AS LSA |
Total number of Demand Circuit Type 5 and Type 11 LSAs. |
DoNotAge...AS LSA |
Total number of Type 5 and Type 11 LSAs with the DoNotAge bit set. |
Number of areas |
Number of areas in router, area addresses, and so on. |
Area BACKBONE |
Backbone is area 0. |
RP/0/0/CPU0:router#show ospf vrf vrf1
VRF vrf1 in Routing Process "ospf 100" with ID 1.1.1.1
NSR (Non-stop routing) is Disabled
Supports only single TOS(TOS0) routes
Supports opaque LSA
It is an area border router
VRF Lite is enabled
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 50 msecs
Minimum hold time between two consecutive SPFs 200 msecs
Maximum wait time between two consecutive SPFs 5000 msecs
Initial LSA throttle delay 50 msecs
Minimum hold time for LSA throttle 200 msecs
Maximum wait time for LSA throttle 5000 msecs
Minimum LSA interval 200 msecs. Minimum LSA arrival 100 msecs
LSA refresh interval 1800 seconds
Flood pacing interval 33 msecs. Retransmission pacing interval 66 msecs
Adjacency stagger enabled; initial (per area): 2, maximum: 64
Number of neighbors forming: 0, 2 full
Maximum number of configured interfaces 1024
Number of external LSA 0. Checksum Sum 00000000
Number of opaque AS LSA 0. Checksum Sum 00000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 2 normal 0 stub 0 nssa
External flood list length 0
SNMP trap is disabled
Area BACKBONE(0)
Number of interfaces in this area is 1
SPF algorithm executed 4 times
Number of LSA 16. Checksum Sum 0x071c6a
Number of opaque link LSA 0. Checksum Sum 00000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Number of LFA enabled interfaces 0, LFA revision 0
Number of Per Prefix LFA enabled interfaces 0
Number of neighbors forming in staggered mode 0, 1 full
Area 1
Number of interfaces in this area is 4
SPF algorithm executed 5 times
Number of LSA 14. Checksum Sum 0x066d93
Number of opaque link LSA 0. Checksum Sum 00000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Number of LFA enabled interfaces 0, LFA revision 0
Number of Per Prefix LFA enabled interfaces 0
Number of neighbors forming in staggered mode 0, 1 full
To display the internal Open Shortest Path First (OSPF) routing table entries to an Area Border Router (ABR) and Autonomous System Boundary Router (ASBR), use the show ospf border-routers command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] border-routers [router-id]
process-name |
(Optional) OSPF process name. If this argument is included, only information for the specified routing process is included. |
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved vrf-names. |
router-id |
(Optional) Router ID associated with the border router. The value of the router-id argument can be any 32-bit router ID value specified in four-part, dotted-decimal notation. No default exists. |
IPv4 and unicast address prefixes
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf border-routers command to list all OSPF border routers visible to the specified processes and to ascertain the OSPF topology of the router.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf border-routers command:
RP/0/0/CPU0:router# show ospf border-routers
OSPF 1 Internal Routing Table
Codes: i - Intra-area route, I - Inter-area route
i 172.31.97.53 [1] via 172.16.1.53, GigabitEthernet 3/0/0/0, ABR/ASBR , Area 0, SPF 3
Field |
Description |
---|---|
i |
Type of this route; i indicates an intra-area route, I an interarea route. |
172.31.97.53 |
Router ID of destination. |
[1] |
Cost of using this route. |
172.16.1.53 |
Next-Next hop toward the destination. |
GigabitEthernet 3/0/0/0 |
Packets destined for 172.16.1.53 are sent over GigabitEthernet interface 3/0/0/0. |
ABR/ASBR |
Router type of the destination; it is either an Area Border Router (ABR) or Autonomous System Boundary Router (ASBR) or both. |
Area 0 |
Area ID of the area from which this route is learned. |
SPF 3 |
Internal number of the shortest path first (SPF) calculation that installs this route. |
To display lists of information related to the Open Shortest Path First (OSPF) database for a specific router, use the show ospf database command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [ adv-router ip-address ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [asbr-summary] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [asbr-summary] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [asbr-summary] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [database-summary]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [external] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [external] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [external] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [network] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [network] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [network] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [nssa-external] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [nssa-external] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [nssa-external] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-area] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-area] [link-state-id] [internal] [adv-router] [ip-address]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-area] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-as] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-as] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-as] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-link] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-link] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [opaque-link] [link-state-id] [internal] [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [router] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [router] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [router] [internal] [self-originate] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [self-originate]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [summary] [link-state-id]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [summary] [link-state-id] [internal] [ adv-router [ip-address] ]
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] database [summary] [link-state-id] [internal] [self-originate] [link-state-id]
IPv4 and unicast address prefixes
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The internal keyword was added. The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The various forms of the show ospf database command deliver information about different OSPF link-state advertisements. This command can be used to examine the link-state database (LSD) and its contents. Each router participating in an area having identical database entries pertaining to that area (with the exception of LSAs that are being flooded). Numerous options (such as network and router ) are used to display portions of the database.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf database command when no arguments or keywords are used:
RP/0/0/CPU0:router# show ospf database
OSPF Router with ID (172.20.1.11) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
172.20.1.8 172.20.1.8 1381 0x8000010D 0xEF60 2
172.20.1.11 172.20.1.11 1460 0x800002FE 0xEB3D 4
172.20.1.12 172.20.1.12 2027 0x80000090 0x875D 3
172.20.1.27 172.20.1.27 1323 0x800001D6 0x12CC 3
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
172.22.1.27 172.20.1.27 1323 0x8000005B 0xA8EE
172.22.1.11 172.20.1.11 1461 0x8000005B 0x7AC
Type-10 Opaque Link Area Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Opaque ID
10.0.0.0 172.20.1.11 1461 0x800002C8 0x8483 0
10.0.0.0 172.20.1.12 2027 0x80000080 0xF858 0
10.0.0.0 172.20.1.27 1323 0x800001BC 0x919B 0
10.0.0.1 172.20.1.11 1461 0x8000005E 0x5B43 1
Field |
Description |
---|---|
Link ID |
Router ID number. |
ADV Router |
ID of the advertising router. |
Age |
Link-state age. |
Seq# |
Link-state sequence number (detects old or duplicate LSAs). |
Checksum |
Fletcher checksum of the complete contents of the LSA. |
Link count |
Number of interfaces detected for the router. |
Opaque ID |
Opaque LSA ID number. |
The following is sample output from the show ospf database command with the asbr-summary keyword:
RP/0/RP0/CPU0:router# show ospf database asbr-summary
OSPF Router with ID (192.168.0.1) (Process ID 300)
Summary ASB Link States (Area 0.0.0.0)
LS age: 1463
Options: (No TOS-capability)
LS Type: Summary Links (AS Boundary Router)
Link State ID: 172.17.245.1 (AS Boundary Router address)
Advertising Router: 172.17.241.5
LS Seq Number: 80000072
Checksum: 0x3548
Length: 28
Network Mask: /0
TOS: 0 Metric: 1
Field |
Description |
---|---|
OSPF Router with ID |
Router ID number. |
Process ID |
OSPF process name. |
LS age |
Link-state age. |
Options |
Type of service options (Type 0 only). |
LS Type |
Link-state type. |
Link State ID |
Link-state ID (ASBR). |
Advertising Router |
ID of the advertising router. |
LS Seq Number |
Link-state sequence (detects old or duplicate LSAs). |
Checksum |
Link-state checksum (Fletcher checksum of the complete contents of the LSA). |
Length |
Length (in bytes) of the LSAs. |
Network Mask |
Network mask implemented. |
TOS |
Type of service. |
Metric |
Link-state metric. |
The following is sample output from the show ospf database command with the external keyword:
RP/0/0/CPU0:router# show ospf database external
OSPF Router with ID (192.168.0.1) (Process ID 300)
Type-5 AS External Link States
LS age: 280
Options: (No TOS-capability)
LS Type: AS External Link
Link State ID: 172.17.0.0 (External Network Number)
Advertising Router: 172.17.70.6
LS Seq Number: 80000AFD
Checksum: 0xC3A
Length: 36
Network Mask: 255.255.0.0
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 1
Forward Address: 0.0.0.0
External Route Tag: 0
Field |
Description |
---|---|
OSPF Router with Router ID |
Router ID number. |
Process ID |
OSPF process name. |
LS age |
Link-state age. |
Options |
Type of service options (Type 0 only). |
LS Type |
Link-state type. |
Link State ID |
Link-state ID (external network number). |
Advertising Router |
ID of the advertising router. |
LS Seq Number |
Link-state sequence number (detects old or duplicate LSAs). |
Checksum |
Link-state checksum (Fletcher checksum of the complete contents of the LSA). |
Length |
Length (in bytes) of the LSA. |
Network Mask |
Network mask implemented. |
Metric Type |
External type. |
TOS |
Type of service. |
Metric |
Link-state metric. |
Forward Address |
Forwarding address. Data traffic for the advertised destination is forwarded to this address. If the forwarding address is set to 0.0.0.0, data traffic is forwarded instead to the originator of the advertisement. |
External Route Tag |
External route tag, a 32-bit field attached to each external route. This tag is not used by the OSPF protocol itself. |
The following is sample output from the show ospf database command with the network keyword:
RP/0/0/CPU0:router# show ospf database network
OSPF Router with ID (192.168.0.1) (Process ID 300)
Net Link States (Area 0.0.0.0)
LS age: 1367
Options: (No TOS-capability)
LS Type: Network Links
Link State ID: 172.23.1.3 (address of Designated Router)
Advertising Router: 192.168.0.1
LS Seq Number: 800000E7
Checksum: 0x1229
Length: 52
Network Mask: /24
Attached Router: 192.168.0.1
Attached Router: 172.23.241.5
Attached Router: 172.23.1.1
Attached Router: 172.23.54.5
Attached Router: 172.23.1.5
Field |
Description |
---|---|
OSPF Router with ID |
Router ID number. |
Process ID |
OSPF process name. |
LS age |
Link-state age. |
Options |
Type of service options (Type 0 only). |
LS Type |
Link-state type. |
Link State ID |
Link-state ID of the designated router. |
Advertising Router |
ID of the advertising router. |
LS Seq Number |
Link-state sequence number (detects old or duplicate LSAs). |
Checksum |
Link-state checksum (Fletcher checksum of the complete contents of the LSA). |
Length |
Length (in bytes) of the LSA. |
Network Mask |
Network mask implemented. |
Attached Router |
List of routers attached to the network, by IP address. |
The following is sample output, carrying Multiprotocol Label Switching traffic engineering (MPLS TE) specification information, from the show ospf database command with the opaque-area keyword and a link-state-id of adv-router:
RP/0/0/CPU0:router# show ospf database opaque-area adv-router 172.20.1.12
OSPF Router with ID (172.20.1.11) (Process ID 1)
Type-10 Opaque Link Area Link States (Area 0)
LS age: 224
Options: (No TOS-capability, DC)
LS Type: Opaque Area Link
Link State ID: 1.0.0.0
Opaque Type: 1
Opaque ID: 0
Advertising Router: 172.20.1.12
LS Seq Number: 80000081
Checksum: 0xF659
Length: 132
Fragment number : 0
MPLS TE router ID : 172.20.1.12
Link connected to Point-to-Point network
Link ID : 172.20.1.11
Interface Address : 172.21.1.12
Neighbor Address : 172.21.1.11
Admin Metric : 10
Maximum bandwidth : 193000
Maximum reservable bandwidth : 125000
Number of Priority : 8
Priority 0 : 125000 Priority 1 : 125000
Priority 2 : 125000 Priority 3 : 125000
Priority 4 : 125000 Priority 5 : 125000
Priority 6 : 125000 Priority 7 : 100000
Affinity Bit : 0x0
Number of Links : 1
The following is sample output from the show ospf database command that displays a Type 10, Router Information LSA:
RP/0/0/CPU0:router# show ospf database opaque-area 4.0.0.0
OSPF Router with ID (3.3.3.3) (Process ID orange)
Type-10 Opaque Link Area Link States (Area 0)
LS age: 105
Options: (No TOS-capability, DC)
LS Type: Opaque Area Link
Link State ID: 4.0.0.0
Opaque Type: 4
Opaque ID: 0
Advertising Router: 3.3.3.3
LS Seq Number: 80000052
Checksum: 0x34e2
Length: 52
Fragment number: 0
Router Information TLV: Length: 4
Capabilities:
Graceful Restart Helper Capable
Traffic Engineering enabled area
All capability bits: 0x50000000
PCE Discovery TLV: Length: 20
IPv4 Address: 3.3.3.3
PCE Scope: 0x20000000
Compute Capabilities:
Inter-area default (Rd-bit)
Compute Preferences:
Intra-area: 0 Inter-area: 0
Inter-AS: 0 Inter-layer: 0
Field |
Description |
---|---|
OSPF Router with ID |
Router ID number. |
Process ID |
OSPF process name. |
LS age |
Link-state age. |
Options |
Type of service options (Type 0 only). |
LS Type |
Link-state type. |
Link State ID |
Link-state ID. |
Opaque Type |
Opaque link-state type. |
Opaque ID |
Opaque ID number. |
Advertising Router |
ID of the advertising router. |
LS Seq Number |
Link-state sequence (detects old or duplicate LSAs). |
Checksum |
Link-state checksum (Fletcher checksum of the complete contents of the LSA). |
Length |
Length (in bytes) of the LSA. |
Fragment number |
Arbitrary value used to maintain multiple traffic engineering LSAs. |
Link ID |
Link ID number. |
Interface Address |
ID address of the interface. |
Neighbor Address |
IP address of the neighbor. |
Admin Metric |
Administrative metric value used by MPLS TE. |
Maximum bandwidth |
Specifies maximum bandwidth (in kbps). |
Maximum reservable bandwidth |
Specifies maximum reservable bandwidth (in kbps). |
Number of Priority |
Priority number. |
Affinity Bit |
Used by MPLS TE. |
Router Information TLV |
Router capabilities are advertised in this TLV. |
Capabilities |
Some router capabilities include stub router, traffic engineering, graceful restart, and graceful restart helper. |
PCE Discovery TLV |
PCE address and capability information is advertised in this TLV. |
IPv4 Address |
Configured PCE IPv4 address. |
PCE Scope |
Computation capabilities of the PCE. |
Compute Capabilities |
Compute capabilities and preferences of the PCE. |
Inter-area default (RD-bit) |
PCE compute capabilities such as intra-area, inter-area, inter-area default, inter-AS, inter-AS default and inter-layer. |
Compute Preferences |
Order or preference of path computation that includes intra-area, inter-area, inter-AS, and inter-layer preferences. |
The following is sample output from the show ospf database command with the router keyword:
RP/0/0/CPU0:router# show ospf database router
OSPF Router with ID (192.168.0.1) (Process ID 300)
Router Link States (Area 0.0.0.0)
LS age: 1176
Options: (No TOS-capability)
LS Type: Router Links
Link State ID: 172.23.21.6
Advertising Router: 172.23.21.6
LS Seq Number: 80002CF6
Checksum: 0x73B7
Length: 120
AS Boundary Router
Number of Links: 8
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 172.23.21.5
(Link Data) Router Interface address: 172.23.21.6
Number of TOS metrics: 0
TOS 0 Metrics: 2
Field |
Description |
---|---|
OSPF Router with ID |
Router ID number. |
Process ID |
OSPF process name. |
LS age |
Link-state age. |
Options |
Type of service options (Type 0 only). |
LS Type |
Link-state type. |
Link State ID |
Link-state ID. |
Advertising Router |
ID of the advertising router. |
LS Seq Number |
Link-state sequence (detects old or duplicate LSAs). |
Checksum |
Link-state checksum (Fletcher checksum of the complete contents of the LSA). |
Length |
Length (in bytes) of the LSA. |
AS Boundary Router |
Definition of router type. |
Number of Links |
Number of active links. |
Link ID |
Link type. |
Link Data |
Router interface address. |
TOS |
Type of service metric (Type 0 only). |
The following is sample output from show ospf database command with the summary keyword:
RP/0/0/CPU0:router# show ospf database summary
OSPF Router with ID (192.168.0.1) (Process ID 300)
Summary Net Link States (Area 0.0.0.0)
LS age: 1401
Options: (No TOS-capability)
LS Type: Summary Links (Network)
Link State ID: 172.23.240.0 (Summary Network Number)
Advertising Router: 172.23.241.5
LS Seq Number: 80000072
Checksum: 0x84FF
Length: 28
Network Mask: /24
TOS: 0 Metric: 1
Field |
Description |
---|---|
OSPF Router with ID |
Router ID number. |
Process ID |
OSPF process name. |
LS age |
Link-state age. |
Options |
Type of service options (Type 0 only). |
LS Type |
Link-state type. |
Link State ID |
Link-state ID (summary network number). |
Advertising Router |
ID of the advertising router. |
LS Seq Number |
Link-state sequence (detects old or duplicate LSAs). |
Checksum |
Link-state checksum (Fletcher checksum of the complete contents of the LSA). |
Length |
Length (in bytes) of the LSA. |
Network Mask |
Network mask implemented. |
TOS |
Type of service. |
Metric |
Link-state metric. |
The following is sample output from show ospf database command with the database-summary keyword:
RP/0/0/CPU0:router# show ospf database database-summary
OSPF Router with ID (172.19.65.21) (Process ID 1)
Area 0 database summary
LSA Type Count Delete Maxage
Router 2 0 0
Network 1 0 0
Summary Net 2 0 0
Summary ASBR 0 0 0
Type-7 Ext 0 0 0
Opaque Link 0 0 0
Opaque Area 0 0 0
Subtotal 5 0 0
Process 1 database summary
LSA Type Count Delete Maxage
Router 2 0 0
Network 1 0 0
Summary Net 2 0 0
Summary ASBR 0 0 0
Type-7 Ext 0 0 0
Opaque Link 0 0 0
Opaque Area 0 0 0
Type-5 Ext 2 0 0
Opaque AS 0 0 0
Total 7 0 0
Field |
Description |
---|---|
LSA Type |
Link-state type. |
Count |
Number of advertisements in that area for each link-state type. |
Delete |
Number of LSAs that are marked “Deleted” in that area. |
Maxage |
Number of LSAs that are marked “Maxaged” in that area. |
To display a list of Open Shortest Path First (OSPF) link-state advertisements (LSAs) waiting to be flooded over an interface, use the show ospf flood-list command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] flood-list [ type interface-path-id ]
process-name |
(Optional) OSPF process name that uniquely identifies an OSPF routing process. The process name is any alphanumeric string no longer than 40 characters. If this argument is included, only information for the specified routing process is included. |
||
vrf |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. |
||
vrf-name |
(Optional) Name of the OSPF VRF. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
||
all |
(Optional) Specifies all OSPF VRF instances. |
||
area-id |
(Optional) Area number used to define the particular area. |
||
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
All interfaces
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.6.0 |
The type interface-path-id arguments were changed from required to optional. The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf flood-list command to display LSAs in flood queue and queue length.
Flood list information is transient and normally the flood lists are empty.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf flood-list command for interface GigabitEthernet 3/0/0/0:
RP/0/0/CPU0:router# show ospf flood-list GigabitEthernet 3/0/0/0
Interface GigabitEthernet3/0/0/0, Queue length 20
Link state retransmission due in 12 msec
Displaying 6 entries from flood list:
Type LS ID ADV RTR Seq NO Age Checksum
5 10.2.195.0 200.0.0.163 0x80000009 0 0xFB61
5 10.1.192.0 200.0.0.163 0x80000009 0 0x2938
5 10.2.194.0 200.0.0.163 0x80000009 0 0x757
5 10.1.193.0 200.0.0.163 0x80000009 0 0x1E42
5 10.2.193.0 200.0.0.163 0x80000009 0 0x124D
5 10.1.194.0 200.0.0.163 0x80000009 0 0x134C
Field |
Description |
---|---|
GigabitEthernet3/0/0/0 |
Interface for which information is displayed. |
Queue length |
Number of LSAs waiting to be flooded. |
Link state retransmission due in |
Length of time (in milliseconds) before next link-state transmission. |
Type |
Type of LSA. |
LS ID |
Link-state ID of the LSA. |
ADV RTR |
IP address of the advertising router. |
Seq NO |
Sequence number of the LSA. |
Age |
Age of the LSA (in seconds). |
Checksum |
Checksum of the LSA. |
To display Open Shortest Path First (OSPF) interface information, use the show ospf interface command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] interface [brief] [ type interface-path-id ]
process-name |
(Optional) OSPF process name that uniquely identifies an OSPF routing process. The process name is any alphanumeric string no longer than 40 characters. If this argument is included, only information for the specified routing process is included. |
vrf |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
all |
(Optional) Specifies all OSPF VRF instances. |
area-id |
(Optional) Area number used to define the particular area. |
brief |
(Optional) Displays brief interface information. |
type |
Interface type. For more information, use the question mark (?) online help function. |
interface-path-id |
Physical interface or virtual interface. Use the show interfaces command to see a list of all interfaces currently configured on the router. For more information about the syntax for the router, use the question mark (?) online help function. |
All interfaces
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.4.1 |
Show output was modified to display multiple area adjacency information configured on an interface. |
Release 3.6.0 |
The brief keyword was added. The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf interface command which includes the topology independent loop free alternates (TI LFA) related information:
RP/0/0/CPU0:router# show ospf interface
GigabitEthernet0/0/0/1 is up, line protocol is up
Internet Address 1.2.2.1/24, Area 0
Process ID 1, Router ID 0.0.0.1, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State BDR, Priority 1, MTU 1500, MaxPktSz 1500
Designated Router (ID) 0.0.0.2, Interface address 1.2.2.2
Backup Designated router (ID) 0.0.0.1, Interface address 1.2.2.
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:02:857
Index 2/2, flood queue length 0
Next 0(0)/0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
LS Ack List: current length 0, high water mark 6
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 0.0.0.2 (Designated Router)
Suppress hello for 0 neighbor(s)
Multi-area interface Count is 0
RP/0/0/CPU0:router#show ospf 1 interface pos 0 /2 /1 /0 POS0/2/1/0 is up, line protocol is up Internet Address 10.111.4.11/24, Area 0 Process ID 100, Router ID 10.11.11.11, Network Type POINT_TO_POINT, Cost: 1 Interface is multi-area adjacency LDP Sync Enabled, Sync Status: Achieved Transmit Delay is 1 sec, State POINT_TO_POINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Non-Stop Forwarding (NSF) enabled Hello due in 00:00:09 Index 5/5, flood queue length 0 Next 0(0)/0(0) Last flood scan length is 4, maximum is 7 Last flood scan time is 0 msec, maximum is 1 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 10.1.1.1 Suppress hello for 0 neighbor(s) Multi-area interface Count is 0 Loopback0 is up, line protocol is up Internet Address 200.2.2.2/32, Area 1 Process ID 1, Router ID 200.2.2.2, Network Type LOOPBACK, Cost: 1 Loopback interface is treated as a stub Host RP/0/RSP0/CPU0:router#
Field |
Description |
---|---|
POS |
Status of the physical link. |
line protocol |
Operational status of the protocol. |
Internet Address |
Interface IP address, subnet mask, and area address. |
Process ID |
OSPF process ID, router ID, network type, and link-state cost. |
LDP Sync Enabled, Sync Status |
LDP Sync configuration state and operational status. Displayed only when the OSPF process is configured for MPLS LDP Sync. |
Transmit Delay |
Transmit delay, interface state, and router priority. |
Timer intervals configured |
Configuration of timer intervals. |
Hello |
Number of seconds until next hello packet is sent over this interface. |
Index 1/1 |
Area and autonomous system flood indexes. |
Next 0x0(0) |
Next area and autonomous system flood information, data pointer, and index. |
Last flood scan length |
Length of last flood scan. |
Last flood scan time |
Time (in milliseconds) of last flood scan. |
Neighbor Count |
Count of network neighbors and list of adjacent neighbors. |
Suppress hello |
Count of neighbors suppressing hello messages. |
Multi-area interface |
Multiple area interface information for the primary interface, such as count and area/neighbor location. |
To display information about the links and fragments available on the local router for traffic engineering, use the show ospf mpls traffic-eng command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] [ type interface-path-id ] mpls traffic-eng { link | fragment }
process-name |
(Optional) OSPF process name that uniquely identifies an OSPF routing process. The process name is any alphanumeric string no longer than 40 characters. If this argument is included, only information for the specified routing process is included. |
||
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
||
area-id |
(Optional) Area number used to define the particular area. |
||
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
||
link |
Provides detailed information about the links over which traffic engineering is supported on the local router. |
||
fragment |
Provides detailed information about the traffic engineering fragments on the local router. |
All links or fragments
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf mpls traffic-eng command when the link keyword is specified:
RP/0/0/CPU0:router# show ospf mpls traffic-eng link
OSPF Router with ID (10.10.10.10) (Process ID 1)
Area 0 has 2 MPLS TE links. Area instance is 67441.
Links in hash bucket 3.
Link is associated with fragment 1. Link instance is 67441
Link connected to Point-to-Point network
Link ID : 10.10.10.8
Interface Address : 10.10.10.2
Neighbor Address : 10.10.10.3
Admin Metric : 0
Maximum bandwidth : 19440000
Maximum global pool reservable bandwidth : 25000000
Maximum sub pool reservable bandwidth : 3125000
Number of Priority : 8
Global pool unreserved BW
Priority 0 : 25000000 Priority 1 : 25000000
Priority 2 : 25000000 Priority 3 : 25000000
Priority 4 : 25000000 Priority 5 : 25000000
Priority 6 : 25000000 Priority 7 : 25000000
Sub pool unreserved BW
Priority 0 : 3125000 Priority 1 : 3125000
Priority 2 : 3125000 Priority 3 : 3125000
Priority 4 : 3125000 Priority 5 : 3125000
Priority 6 : 3125000 Priority 7 : 3125000
Affinity Bit : 0
Links in hash bucket 8.
Link is associated with fragment 0. Link instance is 67441
Link connected to Point-to-Point network
Link ID : 10.1.1.1
Interface Address : 10.10.25.4
Neighbor Address : 10.10.25.5
Admin Metric : 0
Maximum bandwidth : 19440000
Maximum global pool reservable bandwidth : 25000000
Maximum sub pool reservable bandwidth : 3125000
Number of Priority : 8
Global pool unreserved BW
Priority 0 : 25000000 Priority 1 : 25000000
Priority 2 : 25000000 Priority 3 : 25000000
Priority 4 : 25000000 Priority 5 : 25000000
Priority 6 : 25000000 Priority 7 : 25000000
Sub pool unreserved BW
Priority 0 : 3125000 Priority 1 : 3125000
Priority 2 : 3125000 Priority 3 : 3125000
Priority 4 : 3125000 Priority 5 : 3125000
Priority 6 : 3125000 Priority 7 : 3125000
Affinity Bit : 0
Field |
Description |
---|---|
Link ID |
Link type. |
Interface address |
IP address of the interface. |
Neighbor address |
IP address of the neighbor. |
Admin Metric |
Administrative distance metric value used by Multiprotocol Label Switching traffic engineering (MPLS TE). |
Maximum bandwidth |
Bandwidth capacity of the link (in kbps). |
Maximum global pool reservable bandwidth |
Maximum amount of bandwidth that is available for reservation in the global pool. |
Maximum sub pool reservable bandwidth |
Maximum amount of bandwidth that is available for reservation in the subpool. |
Number of Priority |
Priority number. |
Global pool unreserved BW |
Amount of unreserved bandwidth that is available in the global pool. |
Sub pool unreserved BW |
Amount of unreserved bandwidth that is available in the subpool. |
Affinity Bit |
Used by MPLS TE. Attribute values required for links carrying this tunnel. A 32-bit dotted-decimal number. Valid values are from 0x0 to 0xFFFFFFFF, representing 32 attributes (bits), where the value of an attribute is 0 or 1. |
The following is sample output from the show ospf mpls traffic-eng command when the fragment keyword is specified:
RP/0/0/CPU0:router# show ospf mpls traffic-eng fragment
OSPF Router with ID (10.10.10.10) (Process ID 1)
Area 0 has 2 MPLS TE fragment. Area instance is 67441.
MPLS router address is 10.10.10.10
Next fragment ID is 2
Fragment 0 has 1 link. Fragment instance is 67441.
Fragment has 1 link the same as last update.
Fragment advertise MPLS router address
Link is associated with fragment 0. Link instance is 67441
Link connected to Point-to-Point network
Link ID : 10.1.1.1
Interface Address : 10.10.25.4
Neighbor Address : 10.10.25.5
Admin Metric : 0
Maximum bandwidth : 19440000
Maximum global pool reservable bandwidth : 25000000
Maximum sub pool reservable bandwidth : 3125000
Number of Priority : 8
Global pool unreserved BW
Priority 0 : 25000000 Priority 1 : 25000000
Priority 2 : 25000000 Priority 3 : 25000000
Priority 4 : 25000000 Priority 5 : 25000000
Priority 6 : 25000000 Priority 7 : 25000000
Sub pool unreserved BW
Priority 0 : 3125000 Priority 1 : 3125000
Priority 2 : 3125000 Priority 3 : 3125000
Priority 4 : 3125000 Priority 5 : 3125000
Priority 6 : 3125000 Priority 7 : 3125000
Affinity Bit : 0
Fragment 1 has 1 link. Fragment instance is 67441.
Fragment has 0 link the same as last update.
Link is associated with fragment 1. Link instance is 67441
Link connected to Point-to-Point network
Link ID : 10.10.10.8
Interface Address : 10.10.10.2
Neighbor Address : 10.10.10.3
Admin Metric : 0
Maximum bandwidth : 19440000
Maximum global pool reservable bandwidth : 25000000
Maximum sub pool reservable bandwidth : 3125000
Number of Priority : 8
Global pool unreserved BW
Priority 0 : 25000000 Priority 1 : 25000000
Priority 2 : 25000000 Priority 3 : 25000000
Priority 4 : 25000000 Priority 5 : 25000000
Priority 6 : 25000000 Priority 7 : 25000000
Sub pool unreserved BW
Priority 0 : 3125000 Priority 1 : 3125000
Priority 2 : 3125000 Priority 3 : 3125000
Priority 4 : 3125000 Priority 5 : 3125000
Priority 6 : 3125000 Priority 7 : 3125000
Affinity Bit : 0
Field |
Description |
---|---|
Area instance |
Number of times traffic engineering information or any link changed. |
Link instance |
Number of times any link changed. |
Link ID |
Link type. |
Interface address |
IP address of the interface. |
Neighbor address |
IP address of the neighbor. |
Admin Metric |
Administrative distance metric value used by MPLS TE. |
Maximum bandwidth |
Bandwidth capacity of the link (in kbps). |
Maximum global pool reservable bandwidth |
Maximum amount of bandwidth that is available for reservation in the global pool. |
Maximum sub pool reservable bandwidth |
Maximum amount of bandwidth that is available for reservation in the subpool. |
Number of Priority |
Priority number. |
Global pool unreserved BW |
Amount of unreserved bandwidth that is available in the global pool. |
Sub pool unreserved BW |
Amount of unreserved bandwidth that is available in the subpool. |
Affinity Bit |
Used by MPLS TE. Attribute values required for links carrying this tunnel. A 32-bit dotted-decimal number. Valid values are from 0x0 to 0xFFFFFFFF, representing 32 attributes (bits), where the value of an attribute is 0 or 1. |
To display the information about the queue dispatch values, peak lengths, and limits, use the show ospf message-queue command in EXEC mode.
show ospf message-queue
This command has no arguments or keywords.
No default behavior or values
EXEC
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf message-queue command:
RP/0/0/CPU0:router# show ospf 1 message-queue
OSPF 1
Hello Input Queue:
Current queue length: 0
Event scheduled: 0
Total queuing failures: 0
Maximum length : 102
Pkts pending processing: 0
Limit: 5000
Router Message Queue
Current instance queue length: 0
Current redistribution queue length: 0
Current ex spf queue length: 0
Current sum spf queue length: 0
Current intra spf queue length: 0
Event scheduled: 0
Maximum length : 101
Total low queuing failures: 0
Total medium queuing failures: 0
Total high queuing failures: 0
Total instance events: 919
Processing quantum : 300
Low queuing limit: 8000
Medium queuing limit: 9000
High queuing limit: 9500
Rate-limited LSA processing quantum: 150
Current rate-limited LSA queue length: 0
Rate-limited LSA queue peak len: 517
Rate-limited LSAs processed: 4464
Flush LSA processing quantum: 150
Current flush LSA queue length: 0
Flush LSA queue peak len: 274
Rate-limited flush LSAs processed: 420
SPF-LSA-limit processing quantum: 150
Managed timers processing quantum: 50
Instance message count: 0
Instance pulse send count: 919
Instance pulse received count: 919
Global pulse count: 0
Instance Pulse errors: 0
TE Message Queue
Current queue length: 0
Total queuing failures: 0
Maximum length : 0
Number of Dlink errors: 0
Field |
Description |
---|---|
Hello Input Queue |
This section provides statistics on the number of events and incoming packets processed in the Hello (incoming packet) thread of the OSPF process. |
Router Message Queue |
This section provides statistics on the events and messages processed in the Router (primary) thread of the OSPF process. |
TE Message Queue |
This section provides statistics on traffic-engineering events and messages received by OSPF from TE (the te_control process). These events are processed in the Router thread of the OSPF process. |
Number of Dlink errors |
The number of enqueuing or dequeuing errors seen across all the linked-lists in the OSPF process. |
Command |
Description |
---|---|
Limits the number of continuous incoming events processed. |
|
Sets the maximum number of rate-limited link-state advertisements (LSAs) processed per run. |
|
Limits the number of summary or external Type 3 to Type 7 link-state advertisements (LSAs) processed per shortest path first (SPF) run. |
|
Sets the high watermark for incoming priority events. |
To display Open Shortest Path First (OSPF) neighbor information on an individual interface basis, use the show ospf neighbor command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] neighbor [ [ type interface-path-id ] [neighbor-id] [detail] | area-sorted ]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
||
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
||
area-id |
(Optional) Area ID. If you do not specify an area, all areas are displayed. |
||
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
||
neighbor-id |
(Optional) Neighbor ID. |
||
detail |
(Optional) Displays all neighbors given in detail (lists all neighbors). |
||
area-sorted |
(Optional) Specifies that all neighbors are grouped by area. |
All neighbors
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.5.0 |
The area-sorted keyword was added. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf neighbor command showing two lines of summary information for each neighbor:
RP/0/0/CPU0:router# show ospf neighbor
Neighbors for OSPF
Neighbor ID Pri State Dead Time Address Interface
192.168.199.137 1 FULL/DR 0:00:31 172.31.80.37 GigabitEthernet 0/3/0/2
Neighbor is up for 18:45:22
192.168.48.1 1 FULL/DROTHER 0:00:33 192.168.48.1 GigabitEthernet 0/3/0/3
Neighbor is up for 18:45:30
192.168.48.200 1 FULL/DROTHER 0:00:33 192.168.48.200 GigabitEthernet 0/3/0/3
Neighbor is up for 18:45:25
192.168.199.137 5 FULL/DR 0:00:33 192.168.48.189 GigabitEthernet 0/3/0/3
Neighbor is up for 18:45:27
Field |
Description |
---|---|
Neighbor ID |
Neighbor router ID. |
Pri |
Designated router priority. |
State |
OSPF state. |
Dead time |
Time (in hh:mm:ss) that must elapse before OSPF declares the neighbor dead. |
Address |
Address of next hop. |
Interface |
Interface name of next hop. |
Neighbor is up |
Amount of time (in hh:mm:ss) that the OSPF neighbor has been up. |
The following is sample output showing summary information about the neighbor that matches the neighbor ID:
RP/0/0/CPU0:router# show ospf neighbor 192.168.199.137
Neighbor 192.168.199.137, interface address 172.31.80.37
In the area 0.0.0.0 via interface GigabitEthernet 0/3/0/2
Neighbor priority is 1, State is FULL, 6 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x2
Dead timer due in 0:00:32
Neighbor is up for 18:45:30
Number of DBD retrans during last exhange 0
Index 1/1, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum 0 msec
Neighbor 192.168.199.137, interface address 192.168.48.189
In the area 0.0.0.0 via interface GigabitEthernet 0/3/0/3
Neighbor priority is 5, State is FULL, 6 state changes
Options is 0x2
Dead timer due in 0:00:32
Neighbor is up for 18:45:30
Number of DBD retrans during last exhange 0
Index 1/1, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum 0 msec
Total neighbor count: 2
Field |
Description |
---|---|
Neighbor |
Neighbor router ID. |
interface address |
IP address of the interface. |
In the area |
Area and interface through which the OSPF neighbor is known. |
Neighbor priority |
Router priority of neighbor and neighbor state. |
State |
OSPF state. |
state changes |
Number of state changes for this neighbor. |
DR is |
Neighbor ID of the designated router. |
BDR is |
Neighbor ID of the backup designated router. |
Options |
Hello packet options field contents(E-bit only; possible values are 0 and 2; 2 indicates area is not a stub; 0 indicates area is a stub). |
Dead timer |
Time (in hh:mm:ss) to elapse before OSPF declares the neighbor dead. |
Neighbor is up |
Amount of time (in hh:mm:ss) that the OSPF neighbor has been up. |
Number of DBD retrans |
Number of re-sent database description packets. |
Index |
Index and the remaining lines of this command give detailed information about flooding information received from the neighbor. |
If you specify the interface along with the neighbor ID, the software displays the neighbors that match the neighbor ID on the interface, as in the following sample display:
RP/0/0/CPU0:router# show ospf neighbor GigabitEthernet 0/3/0/2 192.168.199.137
Neighbor 192.168.199.137, interface address 172.31.80.37
In the area 0.0.0.0 via interface GigabitEthernet 0/3/0/2
Neighbor priority is 1, State is FULL, 6 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x2
Dead timer due in 0:00:32
Neighbor is up for 18:45:30
Number of DBD retrans during last exhange 0
Index 1/1, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum 0 msec
Total neighbor count: 1
Field |
Description |
---|---|
Neighbor |
Neighbor router ID. |
interface address |
IP address of the interface. |
In the area |
Area and interface through which the OSPF neighbor is known. |
Neighbor priority |
Router priority of the neighbor. |
State |
OSPF state. |
state changes |
Number of state changes for this neighbor. |
DR is |
Neighbor ID of the designated router. |
BDR is |
Neighbor ID of the backup designated router. |
Options |
Hello packet options field contents (E-bit only; possible values are 0 and 2; 2 indicates area is not a stub; 0 indicates area is a stub) |
Dead timer |
Time (in hh:mm:ss) to elapse before OSPF declares the neighbor dead. |
Neighbor is up |
Amount of time (in hh:mm:ss) that the OSPF neighbor has been up. |
Number of DBD retrans |
Number of re-sent database description packets. |
Index |
Index and the remaining lines of this command give detailed information about flooding information received from the neighbor. |
You can also specify the interface without the neighbor ID to show all neighbors on the specified interface, as in the following sample display:
RP/0/0/CPU0:router# show ospf neighbor GigabitEthernet POS 0/3/0/3
Neighbors for OSPF ospf1
ID Pri State Dead Time Address Interface
192.168.48.1 1 FULL/DROTHER 0:00:33 192.168.48.1 GigabitEthernet POS 0/3/0/3
Neighbor is up for 18:50:52
192.168.48.200 1 FULL/DROTHER 0:00:32 192.168.48.200 GigabitEthernet POS 0/3/0/3
Neighbor is up for 18:50:52
192.168.199.137 5 FULL/DR 0:00:32 192.168.48.189 GigabitEthernet POS 0/3/0/3
Neighbor is up for 18:50:52
Total neighbor count: 3
Field |
Description |
---|---|
ID |
Neighbor router ID. |
Pri |
Route priority of the neighbor. |
State |
OSPF state. |
Dead Time |
Time (in hh:mm:ss) to elapse before OSPF declares the neighbor dead. |
Address |
Address of next hop. |
Interface |
Interface name of next hop. |
Neighbor is up |
Time (in hh:mm:ss) that the OSPF neighbor has been up. |
Options |
Hello packet options field contents (E-bit only; possible values are 0 and 2; 2 indicates area is not a stub; 0 indicates area is a stub) |
Dead timer |
Time (in hh:mm:ss) to elapse before OSPF declares the neighbor dead. |
Neighbor is up |
Amount of time (in hh:mm:ss) that the OSPF neighbor has been up. |
Number of DBD retrans |
Number of re-sent database description packets. |
Index |
Index and the remaining lines of this command give detailed information about flooding information received from the neighbor. |
The following samples are from output from the show ospf neighbor detail command:
RP/0/0/CPU0:router# show ospf neighbor detail
Neighbor 192.168.199.137, interface address 172.31.80.37
In the area 0.0.0.0 via interface GigabitEthernet 0/3/0/2
Neighbor priority is 1, State is FULL, 6 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x2
Dead timer due in 0:00:32
Neighbor is up for 18:45:30
Number of DBD retrans during last exhange 0
Index 1/1, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum 0 msec
Total neighbor count: 1
Neighbor 10.1.1.1, interface address 192.168.13.1
In the area 0 via interface GigabitEthernet0/3/0/1
Neighbor priority is 1, State is FULL, 10 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:00:36
Neighbor is up for 1w2d
Number of DBD retrans during last exchange 0
Index 3/3, retransmission queue length 0, number of retransmission 5
First 0(0)/0(0) Next 0(0)/0(0)
Last retransmission scan length is 1, maximum is 1
Last retransmission scan time is 0 msec, maximum is 0 msec
Neighbor 10.4.4.4, interface address 192.168.34.4
In the area 0 via interface GigabitEthernet0/3/0/2
Neighbor priority is 1, State is FULL, 48 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x12
LLS Options is 0x1 (LR)
Dead timer due in 00:00:30
Neighbor is up for 00:40:03
Number of DBD retrans during last exchange 0
Index 2/2, retransmission queue length 0, number of retransmission 6
First 0(0)/0(0) Next 0(0)/0(0)
Last retransmission scan length is 0, maximum is 1
Last retransmission scan time is 0 msec, maximum is 0 msec
Field |
Description |
---|---|
Neighbor |
Neighbor router ID. |
interface address |
IP address of the interface. |
In the area |
Area and interface through which the OSPF neighbor is known. |
Neighbor priority |
Router priority of neighbor and neighbor state. |
State |
OSPF state. |
state changes |
Number of state changes for this neighbor. |
DR is |
Neighbor ID of the designated router. |
BDR is |
Neighbor ID of the backup designated router. |
Options |
Hello packet options field contents. (E-bit only; possible values are 0 and 2; 2 indicates that the area is not a stub; 0 indicates that the area is a stub).) |
LLS Options is 0x1 (LR) |
Neighbor is NFS Cisco capable. |
Dead timer |
Time (in hh:mm:ss) to elapse before OSPF declares the neighbor dead. |
Neighbor is up |
Amount of time (in hh:mm:ss) that the OSPF neighbor has been up. |
Number of DBD retrans |
Number of re-sent database description packets. |
Index |
Index and the remaining lines of this command give detailed information about flooding information received from the neighbor. |
Command |
Description |
---|---|
Configures an OSPF routing process. |
To display the first ten link-state requests pending that the local router is making to the specified Open Shortest Path First (OSPF) neighbor and interface, use the show ospf request-list command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] request-list [ type interface-path-id ] [neighbor-id]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
vrf |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
all |
(Optional) Specifies all OSPF VRF instances. |
area-id |
(Optional) Area ID. If you do not specify an area, all areas are displayed. |
type |
Interface type. For more information, use the question mark (?) online help function. |
i nterface-path-id |
Physical interface or virtual interface. Use the show interfaces command to see a list of all interfaces currently configured on the router. For more information about the syntax for the router, use the question mark (?) online help function. |
neighbor-id |
(Optional) IP address of the OSPF neighbor. |
All neighbors
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You might use this command when the databases of two neighboring routers are out of synchronization or if the adjacency does not form between them. Adjacency means that the routers synchronize their databases when they discover each other.
You can look at the list to determine if one router is trying to request a particular database update. Entries that are suspended in the list usually indicate that updates are not being delivered. One possible reason for this behavior is a maximum transmission unit (MTU) mismatch between the routers.
You might also look at this list to make sure it is not corrupted. The list should refer to database entries that actually exist.
Request list information is transient and normally the lists are empty.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf request-list command:
RP/0/0/CPU0:router# show ospf request-list 10.0.124.4 GigabitEthernet3/0/0/0
Request Lists for OSPF pagent
Neighbor 10.0.124.4, interface GigabitEthernet3/0/0/0 address 10.3.1.2
Type LS ID ADV RTR Seq NO Age Checksum
1 192.168.58.17 192.168.58.17 0x80000012 12 0x0036f3
2 192.168.58.68 192.168.58.17 0x80000012 12 0x00083f
Field |
Description |
---|---|
Neighbor |
Specific neighbor receiving the request list from the local router. |
Interface |
Specific interface over which the request list is being sent. |
Address |
Address of the interface over which the request list is being sent. |
Type |
Type of link-state advertisement (LSA). |
LS ID |
Link-state ID of the LSA. |
ADV RTR |
IP address of the advertising router. |
Seq NO |
Sequence number of the LSA. |
Age |
Age of the LSA (in seconds). |
Checksum |
Checksum of the LSA. |
Command |
Description |
---|---|
Configures an OSPF routing process. |
|
Displays the first ten link-state entries in the retransmission list that the local router sends to the specified neighbor over the specified interface. |
To display the first ten link-state entries in the Open Shortest Path First (OSPF) retransmission list that the local router sends to the specified neighbor over the specified interface, use the show ospf retransmission-list command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] [area-id] retransmission-list [ type interface-path-id ] [neighbor-id]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
||
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
||
area-id |
(Optional) Area ID. If you do not specify an area, all areas are displayed. |
||
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
||
neighbor-id |
(Optional) IP address of the OSPF neighbor. |
All neighbors
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You might use this command when the databases of two neighboring routers are out of synchronization or if the adjacency is not forming between them. Adjacency means that the routers synchronize their databases when they discover each other.
You can look at the list to determine if one router is trying to request a particular database update. Entries that appear to be suspended in the list usually indicate that updates are not being delivered. One possible reason for this behavior is a maximum transmission unit (MTU) mismatch between the routers.
You might also look at this list to make sure it is not corrupted. The list should refer to database entries that actually exist.
Retransmission list information is transient, and normally the lists are empty.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf retransmission-list command:
RP/0/0/CPU0:router# show ospf retransmission-list 10.0.124.4 GigabitEthernet3/0/0/0
Neighbor 10.0.124.4, interface GigabitEthernet3/0/0/0 address 10.3.1.2
Field |
Description |
---|---|
Neighbor |
Specified neighbor receiving the retransmission list from the local router. |
Interface |
Specified interface over which the retransmission list is being sent. |
Address |
Address of the interface. |
Command |
Description |
---|---|
Configures an OSPF routing process. |
|
Displays the first ten link-state requests pending that the local router is making to the specified neighbor and interface. |
To display the Open Shortest Path First (OSPF) topology table, use the show ospf routes command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] routes [ connected | external | local ] [ prefix mask ] [ prefix/length ] [multicast-intact]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
connected |
(Optional) Displays connected routes. |
external |
(Optional) Displays routes redistributed from other protocols. |
local |
(Optional) Displays the local routes redistributed from the Routing Information Base (RIB). |
prefix |
(Optional) IP prefix, which limits output to a specific route. If the prefix argument is specified, either the length or mask argument is required. |
mask |
(Optional) IP address mask. |
/ length |
(Optional) Prefix length, which can be indicated as a slash (/) and number. For example, /8 indicates that the first eight bits in the IP prefix are network bits. If length is used, the slash is required. |
multicast-intact |
(Optional) Displays multicast intact paths. |
All route types
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
The command was changed from show ospf route to show ospf routes. |
Release 3.6.0 |
The multicast-intact keyword was added. The all keyword was added. |
Release 3.9.0 |
Asplain format for 4-byte Autonomous system numbers notation was supported. The input parameters and output were modified to display 4-byte autonomous system numbers and extended communities in either asplain or asdot notations. |
Use the show ospf routes command to display the OSPF private routing table (which contains only routes calculated by OSPF). If there is something wrong with a route in the RIB, then it is useful to check the OSPF copy of the route to determine if it matches the RIB contents. If it does not match, there is a synchronization problem between OSPF and the RIB. If the routes match and the route is incorrect, OSPF has made an error in its routing calculation.
Task ID |
Operations |
---|---|
ospf |
read |
RP/0/0/CPU0:routersh ospf 1 routes 2.2.2.2/32 backup-path
Fri Apr 4 02:08:04.210 PDT
Topology Table for ospf 1 with ID 1.1.1.1
Codes: O - Intra area, O IA - Inter area
O E1 - External type 1, O E2 - External type 2
O N1 - NSSA external type 1, O N2 - NSSA external type 2
O 2.2.2.2/32, metric 3
10.1.0.2, from 2.2.2.2, via GigabitEthernet0/0/0/7, path-id 1
Backup path: TI-LFA, P node: 4.4.4.4, Labels: 16004, 123
10.0.3.2, from 2.2.2.2, via GigabitEthernet0/0/0/3, protected bitmap 0x1
Attribues: Metric: 104, SRLG Disjoint
The following is sample output from the show ospf routes command:
RP/0/0/CPU0:router# show ospf routes
Topology Table for ospf 1 with ID 10.3.4.2
Codes:O - Intra area, O IA - Inter area
O E1 - External type 1, O E2 - External type 2
O N1 - NSSA external type 1, O N2 - NSSA external type 2
O E2 10.3.1.0/24, metric 1
10.3.4.1, from 172.16.10.1, via GigabitEthernet 0/1/0/1
O 10.3.4.0/24, metric 1562
10.3.4.2, directly connected, via GigabitEthernet 0/1/0/1
O E2 10.1.0.0/16, metric 1
10.3.4.1, from 172.16.10.1, via GigabitEthernet 0/1/0/1
O IA 10.10.10.0/24, metric 1572
10.3.4.1, from 172.16.10.1, via GigabitEthernet 0/1/0/1
O E2 130.10.10.0/24, metric 20
10.3.4.1, from 172.16.10.1, via GigabitEthernet 0/1/0/1
Field |
Description |
---|---|
O |
OSPF route. |
E2 |
External Type 2 route. |
10.3.1.0/24 |
Network and subnet mask to which the local router has a route. |
metric 1 |
Cost to reach network 10.3.1.0. |
10.3.4.1 |
Next-hop router on the path to network 10.3.1.0. |
from 172.16.10.1 |
Router ID 172.16.10.1 is the router that advertised this route. |
via POS 0/1/0/1 |
Packets destined for the given prefix (10.3.1.0/24) are sent over POS interface 0/1/0/1. |
The following is sample output from the show ospf routes command with a process name of 100:
RP/0/0/CPU0:router# show ospf 100 routes
Topology Table for ospf 100 with ID 172.23.54.14
Codes:O - Intra area, O IA - Inter area
O E1 - External type 1, O E2 - External type 2
O N1 - NSSA external type 1, O N2 - NSSA external type 2
O 10.1.5.0/24, metric 1562
10.1.5.14, directly connected, via GigabitEthernet 0/3/0/3
O IA 21.0.0.0/24, metric 1572
10.1.5.12, from 172.23.54.12, via GigabitEthernet 0/3/0/3
O 10.0.0.0/24, metric 10
10.0.0.12, directly connected, via GigabitEthernet 0/2/0/3
Field |
Description |
---|---|
O |
OSPF route. |
IA |
Interarea route. |
10.1.5.0/24 |
Network and subnet mask to which the local router has a route. |
metric 1562 |
Cost to reach network 10.1.5.0. |
10.1.5.14 |
Next-hop router on the path to network 10.1.5.0. |
from 172.23.54.12 |
Router ID 172.23.54.12 is the router that advertised this route. |
via GigabitEthernet 0/3/0/3 |
Packets destined for the given prefix (10.3.1.0/24) are sent over GigabitEthernet interface 0/3/0/3. |
The following is sample output from the show ospf routes command with a prefix of 10.0.0.0 and a length of 24:
RP/0/0/CPU0:router# show ospf routes 10.0.0.0/24
Topology Table for ospf 100 with ID 172.23.54.14
Codes:O - Intra area, O IA - Inter area
O E1 - External type 1, O E2 - External type 2
O N1 - NSSA external type 1, O N2 - NSSA external type 2
O IA 10.0.0.0/24, metric 1572
10.1.5.12, from 172.23.54.12, via GigabitEthernet 0/3/0/3
Field |
Description |
---|---|
O |
Route is an OSPF route. |
IA |
Route to network 10.0.0.0 is an interarea route. |
10.0.0.0/24 |
Network and subnet mask to which the local router has a route. |
metric 1572 |
Cost to reach network 10.0.0.0. |
10.1.5.12 |
IP address of next-hop router on the path to network 10.0.0.0. |
from 172.23.54.12 |
Router ID 172.23.54.12 is the router that advertised this route. |
via GigabitEthernet 0/3/0/3 |
Packets destined for the given prefix (10.0.0.0/24) are sent over GigabitEthernet interface 0/3/0/3. |
Command |
Description |
---|---|
Configures an OSPF routing process. |
|
Displays current routes information in the Routing Information Base (RIB). |
|
Displays opaque data installed in the Routing Information Base (RIB). |
To display Open Shortest Path First (OSPF) sham-link information, use the show ospf sham-links command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] sham-links
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
vrf |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. |
vrf-name |
(Optional) Name of the OSPF VRF. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
all |
(Optional) Specifies all OSPF VRF instances. |
No default behavior or values
EXEC
Release |
Modification |
---|---|
Release 3.6.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf sham-links command to display OSPF sham-link information.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf sham-links command:
RP/0/0/CPU0:router# show ospf 1 vrf vrf_1 sham-links
Sham Links for OSPF 1, VRF vrf_1
Sham Link OSPF_SL0 to address 10.0.0.3 is up
Area 0, source address 10.0.0.1
IfIndex = 185
Run as demand circuit
DoNotAge LSA allowed., Cost of using 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:04
Adjacency State FULL (Hello suppressed)
Number of DBD retrans during last exchange 0
Index 2/2, retransmission queue length 0, number of retransmission 0
First 0(0)/0(0) Next 0(0)/0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
Keychain-based authentication enabled
Key id used is 2
Field |
Description |
---|---|
Sham Link OSPF_SL0 to address |
Address of the destination endpoint of the sham link. |
IfIndex |
ifindex associated with the sham link. |
Run as demand circuit |
Sham link is treated as a demand circuit. |
DoNotAge LSA allowed |
DoNotAge LSAs are allowed to be flooded over the sham link. |
Cost of using |
Sham-link cost. |
Transmit Delay |
Sham-link transmit delay. |
State |
Sham-link interface state. |
Timer intervals configured |
Various sham-link interface-related timers. |
Hello due in |
Time before the next Hello is sent over the sham link. |
Adjacency State |
State of the adjacency with the neighbor over the sham link. |
Number of DBD retrans during last exchange |
Number of DBD retransmissions during the last exchange over the sham link. |
Index |
Area flood index. |
retransmission queue length |
Retransmission queue length on the sham link. |
number of retransmission |
Number of retransmissions over the sham-link interface. |
First |
First flood information. |
Next |
Next flood information. |
Last retransmission scan length is |
Last retransmission scan length on the sham-link interface. |
maximum is |
Maximum retransmission scan length on the sham-link interface. |
Last retransmission scan time is |
Last retransmission scan time on the sham-link interface. |
maximum is 0 msec |
Maximum retransmission scan time on the sham-link interface. |
Keychain-based authentication enabled |
Keychain-based authentication is enabled. |
Key id used is |
Key ID used. |
To display the per interface statistics for OSPFv2, use the show ospf statistics interface command in EXEC mode.
show ospf [ process name [ area id ] ] [ vrf { vrf-name | all } ] [ area id ] statistics interface [ interface name | summary-only ]
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
area id |
(Optional) Area number used to define the particular area. |
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
summary-only |
(Optional) Displays only the summary statistics for the given instance or area (if specified). |
No default behavior or values.
EXEC
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf statistics interface command:
RP/0/0/CPU0:router# show ospf 0 1.1.1.1 statistics interface
Interface POS0/3/0/0 Process ID 0 Area 1.1.1.1
Multi-Adjacency Interface
OSPF packet and LSA statistics
RX(hello) RX(router) TX LSA RX LSA TX
Hello 32 - 33 - -
DB Des 3 3 2 2 4
LS Req 0 0 1 0 0
LS Upd 5 5 3 18 10
LS Ack 1 1 3 10 18
TOTAL 41 9 42 30 32
OSPF Header Errors
Version 0 LLS 0
Type 0 Auth RX 0
Length 0 Auth TX 0
Checksum 0
OSPF LSA Errors
Type 0 Checksum 0
Length 0 Data 0
OSPF Errors
Bad Source 0 Area Mismatch 0
No Virtual Link 0 Self Originated 0
No Sham Link 0 Duplicate ID 0
Nbr ignored 0 Graceful Shutdown 0
Unknown nbr 0 Passive intf 0
No DR/BDR 0 Disabled intf 0
Enqueue 0 Unspecified RX 0
Socket 0 Unspecified TX 0
Field |
Description |
---|---|
OSPF packet and LSA statistics |
Packets and LSAs received and transmitted on a given interface. |
OSPF Header Errors |
OSPF packets discarded due to the error in the OSPF header. |
OSPF LSA Errors |
OSPF LSAs discarded due to the error in the OSPF LSA header. |
OSPF Errors |
Packets discarded or errors encountered during handling OSPF packets on the given interface. |
Command |
Description |
---|---|
Clears the Open Shortest Path First (OSPF) statistics per interface. |
To display Open Shortest Path First (OSPF) aggregated summary address information, use the show ospf summary-prefix command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] summary-prefix
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
All summary prefixes
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf summary-prefix command if you configured summarization of external routes with the summary-prefix command and you want to display configured summary addresses.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf summary-prefix command:
RP/0/0/CPU0:router# show ospf summary-prefix
OSPF Process 1, summary-prefix
10.1.0.0/255.255.0.0 Metric 20, Type 2, Tag 0
Field |
Description |
---|---|
10.1.0.0/255.255.0.0 |
Summary address designated for a range of addresses. The IP subnet mask used for the summary route. |
Metric |
Metric used to advertise the summary routes. |
Type |
External link-state advertisements (LSA) metric type. |
Tag |
Tag value that can be used as a “match” value for controlling redistribution through route maps. |
Command |
Description |
---|---|
Configures an OSPF routing process. |
|
Creates aggregate addresses for routes being redistributed from another routing protocol into the OSPF protocol. |
To display parameters and the current state of Open Shortest Path First (OSPF) virtual links, use the show ospf virtual-links command in EXEC mode.
show ospf [process-name] [ vrf { vrf-name | all } ] virtual-links
process-name |
(Optional) Name that uniquely identifies an OSPF routing process. The process name is defined by the router ospf command. If this argument is included, only information for the specified routing process is displayed. |
vrf vrf-name all |
(Optional) Specifies an OSPF VPN routing and forwarding (VRF) instance. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
All virtual links
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.6.0 |
The all keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf virtual-links command to display useful information for debugging OSPF routing operations.
Task ID |
Operations |
---|---|
ospf |
read |
The following is sample output from the show ospf virtual-links command:
RP/0/0/CPU0:router# show ospf virtual-links
Virtual Link to router 172.31.101.2 is up
Transit area 0.0.0.1, via interface GigabitEthernet 0/3/0/0, Cost of using 10
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 0:00:08
Adjacency State FULL
Field |
Description |
---|---|
Virtual Link to router 172.31.101.2 is up |
OSPF neighbor and whether the link to that neighbor is up or down. |
Transit area 0.0.0.1 |
Transit area through which the virtual link is formed. |
via interface GigabitEthernet 0/3/0/0 |
Interface through which the virtual link is formed. |
Cost of usingusing 10 |
Cost of reaching the OSPF neighbor through the virtual link. |
Transmit Delay is 1 sec |
Transmit delay (in seconds) on the virtual link. |
State POINT_TO_POINT |
State of the OSPF neighbor. |
Timer intervals |
Various timer intervals (in seconds) configured for the link. |
Hello due in 0:00:08 |
When the next hello message is expected from the neighbor (in hh:mm:ss). |
Adjacency State FULL |
Adjacency state between the neighbors. |
Command |
Description |
---|---|
Configures an OSPF routing process. |
To display information about the OSPFv2 processes running on the router, use the show protocols command in EXEC mode.
show protocols [ afi-all | ipv4 | ipv6 ] [ all | protocol ]
afi-all |
(Optional) Specifies all address families. |
ipv4 |
(Optional) Specifies an IPv4 address family. |
ipv6 |
(Optional) Specifies an IPv6 address family. |
all |
(Optional) Specifies all protocols for a given address family. |
protocol |
(Optional) Specifies a routing protocol. For the IPv4 address family, the options are: For the IPv6 address family, the options are: |
No default behavior or value
EXEC
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced |
Release 3.6.0 |
The eigrp and rip protocols were supported. |
Release 3.9.0 |
Asplain format for 4-byte Autonomous system numbers notation was supported. The input parameters and output were modified to display 4-byte autonomous system numbers and extended communities in either asplain or asdot notations. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read |
rib |
read |
The following is an OSPF configuration and the resulting show protocols ospf display:
RP/0/0/CPU0:router#show running router ospf 1 router ospf 1 router-id Loopback0 nsf redistribute connected redistribute isis 3 area 0 mpls traffic-eng interface Loopback0 ! interface Loopback1 ! interface Loopback2 ! interface GigabitEthernet 0/3/0/0 ! interface GigabitEthernet 0/3/0/1 ! interface GigabitEthernet 0/3/0/2 ! interface GigabitEthernet 0/3/0/3 ! ! mpls traffic-eng router-id Loopback0 ! RP/0/0/CPU0:router# show protocols ospf Routing Protocol OSPF 1 Router Id: 55.55.55.55 Distance: 110 Non-Stop Forwarding: Enabled Redistribution: connected isis 3 Area 0 MPLS/TE enabled GigabitEthernet 0/3/0/3 GigabitEthernet 0/3/0/2 GigabitEthernet 0/3/0/1 GigabitEthernet 0/3/0/0 Loopback2 Loopback0
Field |
Description |
---|---|
Router Id |
ID of the router for this configuration. |
Distance |
Administrative distance of OSPF routes relative to routes from other protocols. |
Non-Stop Forwarding |
Status of nonstop forwarding. |
Redistribution |
Lists the protocols that are being redistributed. |
Area |
Information about the current area including list of interfaces and the status of Multiprotocol Label Switching traffic engineering (MPLS TE). |
To specify an SNMP context for an OSPF instance, use the snmp context command in router configuration mode or in VRF configuration mode. To remove the SNMP context, use the no form of this command.
snmp context context_name
no snmp context context_name
context_name |
Specifies name of the SNMP context for OSPF instance. |
SNMP context is not specified.
Router configuration
VRF configuration
Release | Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The snmp-server commands need to be configured to perform SNMP request for the OSPF instance. Refer SNMP Server Commands module in Cisco IOS XR System Management Command Reference for the Cisco XR 12000 Series Router for information on using the snmp-server commands.
Note | To map an SNMP context with a protocol instance, topology or VRF entity, use the snmp-server context mapping command. However, the feature option of this command does not work with OSPF protocol. |
Task ID | Operation |
---|---|
ospf |
read, write |
This example shows how to configure an SNMP context foo for OSPF instance 100:
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#snmp context foo
RP/0/0/CPU0:router(config)#snmp-server host 10.0.0.2 traps version 2c public udp-port 1620 RP/0/0/CPU0:router(config)#snmp-server community public RW RP/0/0/CPU0:router(config)#snmp-server contact foo RP/0/0/CPU0:router(config)#snmp-server community-map public context foo
snmp-server host 10.0.0.2 traps version 2c public udp-port 1620 snmp-server community public RW snmp-server contact foo snmp-server community-map public context foo router ospf 100 router-id 2.2.2.2 bfd fast-detect nsf cisco snmp context foo area 0 interface Loopback1 ! ! area 1 interface GigabitEthernet0/2/0/1 demand-circuit enable ! interface GigabitEthernet0/3/0/0 ! interface GigabitEthernet0/3/0/1 ! ! !
Command | Description |
---|---|
snmp trap (OSPF) |
Enables SNMP trap for an OSPF instance |
snmp-server host |
Specifies the recipient of an SNMP notification operation. |
snmp-server community |
Configures the community access string to permit access to the Simple Network Management Protocol (SNMP). |
snmp-server contact |
Sets the Simple Network Management Protocol (SNMP) system contact. |
snmp-server community-map |
Associates a Simple Network Management Protocol (SNMP) community with an SNMP context. |
To enable SNMP trap for an OSPF instance, use the snmp trap command in VRF configuration mode. To disable SNMP trap for the OSPF instance, use the no form of this command.
snmp trap
no snmp trap
This command has no keywords or arguments.
Disabled.
VRF configuration
Release | Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
ospf |
read, write |
This example shows how to enable SNMP trap for OSPF instance 100 under VRF vrf-1:
RP/0/0/CPU0:router#configure RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#vrf vrf-1 RP/0/0/CPU0:router(config-ospf-vrf)#snmp trap
Command | Description |
| Specifies SNMP context for an OSPF instance. |
To control the number of traps that OSPF sends by configuring window size and the maximum number of traps during that window, use the snmp trap rate-limit command in router configuration mode. To disable configuring the window size and maximum number of traps during the window, use the no form of this command.
snmp trap rate-limit window-size max-num-traps
no snmp trap rate-limit window-size max-num-traps
window-size |
Specifies the trap rate limit sliding window size. |
max-num-traps |
Specifies the maximum number of traps sent in window time. |
None
Router configuration
Release | Modification |
---|---|
Release 3.9.0 |
This command was introduced. This command replaces the snmp-server trap ospf rate-limit command. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
ospf |
read,write |
RP/0/0/CPU0:router(config)#router ospf 100 RP/0/0/CPU0:router(config-ospf)#snmp trap rate-limit 30 100
To prioritize OSPFv2 prefix installation into the global Routing Information Base (RIB) during Shortest Path First (SPF) run, use the spf prefix-priority command in router configuration mode. To return to the system default value, use the no form of this command.
spf prefix-priority route-policy policy-name
no spf prefix-priority route-policy policy-name
route-policy policy-name |
Specifies the route policy to apply to OSPFv2 prefix prioritization.
|
SPF prefix prioritization is disabled.
OSPF router configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
SPF prefix prioritization is disabled, by default. In disabled mode, the /32 prefixes are installed into the global RIB before other prefixes.
If SPF prefix prioritization is enabled, routes are matched against the route-policy criteria and are assigned to the appropriate priority queue based on the spf-priority set. Unmatched prefixes, including the /32 prefixes, are placed in the low-priority queue.
If all /32 prefixes are desired in the high-priority queue or medium-priority queue, configure the following single route map:
prefix-set ospf-medium-prefixes 0.0.0.0/0 ge 32 end-set
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure OSPFv2 SPF prefix prioritization:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# prefix-set ospf-critical-prefixes RP/0/0/CPU0:router(config-pfx)# 66.0.0.0/16 RP/0/0/CPU0:router(config-pfx)# end-set RP/0/0/CPU0:router(config)# route-policy ospf-spf-priority RP/0/0/CPU0:router(config-rpl)# if destination in ospf-critical-prefixes then set spf-priority critical endif RP/0/0/CPU0:router(config-rpl)# end-policy RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# router-id 66.0.0.1 RP/0/0/CPU0:router(config-ospf)# spf prefix-priority route-policy ospf-spf-priority
Command |
Description |
---|---|
prefix-set |
Enters prefix set configuration mode and defines a prefix set. |
route-policy (RPL) |
Defines a route policy and enters route-policy configuration mode. |
To define an area as a stub area, use the stub command in area configuration mode. To disable this function, use the no form of this command.
stub [no-summary]
no stub
no-summary |
(Optional) Prevents an Area Border Router (ABR) from sending summary link advertisements into the stub area. |
No stub area is defined.
Area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You must configure the stub command on all routers in the stub area.
Use the default-cost command on the ABR of a stub area to specify the cost of the default route advertised into the stub area by the ABR.
To further reduce the number of link-state advertisements (LSAs) sent into a stub area, you can configure the no-summary keyword on the ABR to prevent it from sending summary LSAs (LSA Type 3) into the stub area.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to assign a default cost of 20 to stub network 10.0.0.0:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# area 10.0.0.0 RP/0/0/CPU0:router(config-ospf-ar)# stub RP/0/0/CPU0:router(config-ospf-ar)# default-cost 20 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/3/0/3
Command |
Description |
---|---|
Enables authentication for an OSPF area. |
|
Specifies a cost for the default summary route sent into a stub area. |
To create aggregate addresses for routes being redistributed from another routing protocol into the Open Shortest Path First (OSPF) protocol, use the summary-prefix command in the appropriate mode. To stop summarizing redistributed routes, use the no form of the command.
summary-prefix address mask [ not-advertise | tag tag ]
no summary-prefix address mask
address |
Summary address designated for a range of addresses. |
mask |
IP subnet mask used for the summary route. |
not-advertise |
(Optional) Suppresses summary routes that match the address and mask pair from being advertised. |
tag tag |
(Optional) Tag value that can be used as a “match” value for controlling redistribution through route policies. |
When this command is not used, specific addresses are created for each route from another route source being distributed into the OSPF protocol.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the summary-prefix command to cause an OSPF Autonomous System Boundary Router (ASBR) to advertise one external route as an aggregate for all redistributed routes that are covered by the address. This command summarizes only routes from other routing protocols that are being redistributed into OSPF.
You can use this command multiple times to summarize multiple groups of addresses. The metric used to advertise the summary is the lowest metric of all the more specific routes. This command helps reduce the size of the routing table.
If you want to summarize routes between OSPF areas, use the range command.
Task ID |
Operations |
---|---|
ospf |
read, write |
In the following example, summary address 10.1.0.0 includes address 10.1.1.0, 10.1.2.0, 10.1.3.0, and so on. Only the address 10.1.0.0 is advertised in an external link-state advertisement.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# summary-prefix 10.1.0.0 255.255.0.0
Command |
Description |
---|---|
Consolidates and summarizes routes at an area boundary. |
To change the interval at which Open Shortest Path First (OSPF) link-state advertisements (LSAs) are collected into a group and refreshed, checksummed, or aged, use the timers lsa group-pacing command in the appropriate mode. To restore the default value, use the no form of this command.
timers lsa group-pacing seconds
no timers lsa group-pacing
seconds |
Interval (in seconds) at which LSAs are grouped and refreshed, checksummed, or aged. Range is 10 seconds to 1800 seconds. |
seconds : 240 seconds
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
OSPF LSA group pacing is enabled by default. For typical customers, the default group pacing interval for refreshing, checksumming, and aging is appropriate and you need not configure this feature.
The duration of the LSA group pacing is inversely proportional to the number of LSAs the router is handling. For example, if you have approximately 10,000 LSAs, decreasing the pacing interval would benefit you. If you have a very small database (40 to 100 LSAs), increasing the pacing interval to 10 to 20 minutes might benefit you slightly.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to change the OSPF pacing between LSA groups to 60 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# timers lsa group-pacing 60
To limit the frequency that new instances of any particular Open Shortest Path First (OSPF) link-state advertisements (LSAs) can be accepted during flooding, use the timers lsa min-arrival command in the appropriate mode. To restore the default value, use the no form of this command.
timers lsa min-arrival milliseconds
no timers lsa min-arrival
milliseconds |
Minimum interval (in milliseconds) between accepting same LSA. Range is 0 to 600000 milliseconds. |
milliseconds : 100 milliseconds
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.6.0 |
The minimum LSA arrival unit was changed to milliseconds. The default minimum LSA arrival interval was set to 100 milliseconds. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to change the minimum interval between accepting the same LSA to 2 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# timers lsa min-arrival 2
To configure the time interval at which Open Shortest Path First (OSPF) self-originated link-state advertisements (LSAs) are refreshed, use the timers lsa refresh command in an appropriate configuration mode. To restore the default value, use the no form of this command.
timers lsa refresh seconds
no timers lsa refresh
seconds |
How often self-originated LSAs should be refreshed, in seconds. Range is 1800 to 2700 seconds. |
seconds : 1800 seconds.
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
timers lsa refresh command allows self-originated LSAs to be refreshed at non-standard times, anywhere from 1800 to 2700 seconds. Higher refresh interval value may gradually lead to lower CPU utilization by OSPF process.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure an LSA refresh interval of 1800 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 100 RP/0/0/CPU0:router(config-ospf)# timers lsa refresh 1800
Command |
Description |
---|---|
Change the interval at which Open Shortest Path First (OSPF) link-state advertisements (LSAs) are collected into a group and refreshed, checksummed, or aged. |
|
Limits the frequency that new instances of any particular Open Shortest Path First (OSPF) link-state advertisements (LSAs) can be accepted during flooding. |
To modify the Open Shortest Path First (OSPF) link-state advertisement (LSA) throttling, use the timers throttle lsa all command in the appropriate mode. To revert LSA throttling to default settings, use the no form of this command
timers throttle lsa all start-interval hold-interval max-interval
no timers throttle lsa all
start-interval |
Delay to generate first occurance of LSA in milliseconds. Range is 0 to 600000 milliseconds. |
hold-interval |
Minimum delay between originating the same LSA in milliseconds. Range is 1 to 600000 milliseconds. |
max-interval |
Maximum delay between originating the same LSA in milliseconds. Range is 1 to 600000 milliseconds. |
start-interval : 50 milliseconds
hold-interval : 200 milliseconds
max-interval : 5000 milliseconds
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The lsa-start time is the delay before flooding the first instance of an LSA. The lsa-hold interval is the minimum time to elapse before flooding an updated instance of an LSA. The lsa-max-wait time is the maximum time that can elapse before flooding an updated instance of an LSA.
For quick convergence, use smaller times for the lsa-start time and lsa-hold interval. However, in relatively large networks, this may result in a large number of LSAs being flooded in a relatively short time. A balance with the lsa-start time and lsa-hold interval can be iteratively arrived at for the size of your network. The lsa-max-wait time can be used to ensure that OSPF reconverges within a reasonable amount of time.
Note | LSA throttling is always enabled. You can change the timer values with the timers throttle lsa all command or specify the no keyword to revert back to the default settings. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to change the start, hold, and maximum wait interval values to 500, 1000, and 90,000 milliseconds, respectively:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# timers throttle lsa all 500 1000 90000
The following example is output from the show ospf command that displays the modified LSA throttle settings:
RP/0/0/CPU0:router# show ospf Routing Process "ospf 1" with ID 1.1.1.1 Supports only single TOS(TOS0) routes Supports opaque LSA It is an area border router Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs 10000 msecs Maximum wait time between two consecutive SPFs 10000 msecs Initial LSA throttle delay 500 msecs Minimum hold time for LSA throttle 1000 msecs Maximum wait time for LSA throttle 90000 msecs Minimum LSA interval 1000 msecs. Minimum LSA arrival 1 secs Maximum number of configured interfaces 255 Number of external LSA 0. Checksum Sum 00000000 Number of opaque AS LSA 0. Checksum Sum 00000000 Number of DCbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 2. 2 normal 0 stub 0 nssa External flood list length 0 Non-Stop Forwarding enabled Area BACKBONE(0) (Inactive) Number of interfaces in this area is 2 SPF algorithm executed 8 times Number of LSA 2. Checksum Sum 0x01ba83 Number of opaque link LSA 0. Checksum Sum 00000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0 Area 1 Number of interfaces in this area is 1 SPF algorithm executed 9 times Number of LSA 2. Checksum Sum 0x0153ea Number of opaque link LSA 0. Checksum Sum 00000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0
Command |
Description |
---|---|
Displays generic information about OSPF routing processes. |
To modify the Open Shortest Path First (OSPF) shortest path first (SPF) throttling, use the timers throttle spf command in the appropriate mode. To revert SPF throttling to default settings, use the no form of this command.
timers throttle spf spf-start spf-hold spf-max-wait
no timers throttle spf
spf-start |
Initial SPF schedule delay (in milliseconds). Range is 1 to 600000 milliseconds. |
spf-hold |
Minimum hold time (in milliseconds) between two consecutive SPF calculations. Range is 1 to 600000 milliseconds. |
spf-max-wait |
Maximum wait time (in milliseconds) between two consecutive SPF calculations. Range is 1 to 600000 milliseconds. |
spf-start:50 milliseconds
spf-hold: 200 milliseconds
spf-max-wait: 5000 milliseconds
Router configuration
VRF configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The spf-start time is the delay before running SPF for the first time. The spf-hold interval is the minimum time to elapse between subsequent SPF runs. The spf-max-wait time is the maximum time that can elapse before running SPF again.
Tip | Setting a low spf-start time and spf-hold time causes routing to switch to the alternate path more quickly if there is a failure; however, it consumes more CPU processing time. |
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to change the start, hold, and maximum wait interval values to 5, 1000, and 90000 milliseconds, respectively:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# timers throttle spf 5 1000 90000
To set the estimated time required to send a link-state update packet on the interface, use the transmit-delay command in the appropriate mode. To return to the default value, use the no form of this command.
transmit-delay seconds
no transmit-delay seconds
seconds |
Time (in seconds) required to send a link-state update. Range is 1 to 65535 seconds. |
seconds: 1 second
Router configuration
Area configuration
Interface configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
Release 3.3.0 |
This command was added under the VRF configuration mode. |
Release 3.4.1 |
This command was added under the multi-area interface configuration mode. |
Release 3.6.0 |
The command was added under sham-link configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Link-state advertisements (LSAs) in the update packet must have their ages incremented by the amount specified in the seconds argument before transmission. The value assigned should take into account the transmission and propagation delays for the interface.
If the delay is not added before transmission over a link,the time in which the LSA propagates over the link is not considered. This setting has significance only on very low-speed networks not supported in Cisco IOS XR software or on networks such as satellite circuits that incur a very long (greater than one second) delay time.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure a transmit delay for interface GigabitEthernet 0/3/0/0:
RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# area 0 RP/0/0/CPU0:router(config-ospf-ar)# interface GigabitEthernet 0/3/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# transmit-delay 3
Command |
Description |
---|---|
Displays general information about OSPF routing processes. |
To define an Open Shortest Path First (OSPF) virtual link, use the virtual-link command in area configuration mode. To remove a virtual link, use the no form of this command.
virtual-link router-id
no virtual-link router-id
router-id |
Router ID associated with the virtual link neighbor. The router ID appears in the show ospf command display. The router ID can be any 32-bit router ID value specified in four-part, dotted-decimal notation. |
No virtual links are defined.
Area configuration
Release |
Modification |
---|---|
Release 3.2 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
All areas in an OSPF autonomous system must be physically connected to the backbone area (area 0). In some cases in which this physical connection is not possible, you can use a virtual link to connect to the backbone through a nonbackbone area. You can also use virtual links to connect two parts of a partitioned backbone through a nonbackbone area. The area through which you configure the virtual link, known as a transit area, must have full routing information. The transit area cannot be a stub or not-so-stubby area.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to establish a virtual link with default values for all optional parameters:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# area 10.0.0.0 RP/0/0/CPU0:router(config-ospf-ar)# virtual-link 10.3.4.5 RP/0/0/CPU0:router(config-ospf-ar-vl)#
The following example shows how to establish a virtual link with clear text authentication called mykey:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 201 RP/0/0/CPU0:router(config-ospf)# area 10.0.0.0 RP/0/0/CPU0:router(config-ospf-ar)# virtual-link 10.3.4.5 RP/0/0/CPU0:router(config-ospf-ar-vl)# authentication-key 0 mykey
Command |
Description |
---|---|
Enables authentication for an OSPF area. |
|
Displays parameters and the current state of OSPF virtual links |
To configure an Open Shortest Path First (OSPF) VPN routing and forwarding (VRF) instance, use the vrf command in router configuration mode. To terminate an OSPF VRF, use the no form of this command.
vrf vrf-name
no vrf vrf-name
vrf-name |
Identifier of an OSPF VRF. The vrf-name argument can be specified as an arbitrary string. The strings “default” and “all” are reserved VRF names. |
No OSPF VRF is defined.
Router configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the vrf command to explicitly configure a VRF. Commands configured under the VRF configuration mode (such as the interface [OSPF] and authentication commands) are automatically bound to that VRF.
To modify or remove the VRF, the vrf-id argument format must be the same as the format used when creating the area.
Note | To remove the specified VRF from the router configuration, use the no vrf vrf-id command. The no vrf vrf-id command removes the VRF and all VRF options, such as authentication , default-cost , nssa , range , stub , virtual-link , and interface. |
To avoid possibly having the router ID change under a VRF, explicitly configure the router ID using the router-id command.
Task ID |
Operations |
---|---|
ospf |
read, write |
The following example shows how to configure VRF vrf1 and GigabitEthernet interface 0/2/0/0. GigabitEthernet interface 0/2/0/0 is bound to VRF vrf1 automatically.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf)# vrf vrf1 RP/0/0/CPU0:router(config-ospf-vrf)# area area1 RP/0/0/CPU0:router(config-ospf-vrf-ar)# interface GigabitEthernet 0/2/0/0
Command |
Description |
---|---|
Configures a router ID for an OSPF process. |