Contents
OSPF Commands on Cisco IOS XR Software
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 .
- address-family (OSPF)
- adjacency stagger
- area (OSPF)
- authentication (OSPF)
- authentication-key (OSPF)
- auto-cost (OSPF)
- capability opaque disable
- clear ospf process
- clear ospf redistribution
- clear ospf routes
- clear ospf statistics
- clear ospf statistics interface
- cost (OSPF)
- cost-fallback (OSPF)
- database-filter all out (OSPF)
- dead-interval (OSPF)
- default-cost (OSPF)
- default-information originate (OSPF)
- default-metric (OSPF)
- demand-circuit (OSPF)
- disable-dn-bit-check
- distance (OSPF)
- distance ospf
- distribute-list
- domain-id
- domain-tag
- flood-reduction (OSPF)
- hello-interval (OSPF)
- ignore lsa mospf
- fast-reroute per-link
- fast-reroute per-link exclude interface
- interface (OSPF)
- log adjacency changes (OSPF)
- loopback stub-network
- max-lsa
- max-metric
- maximum interfaces (OSPF)
- maximum paths (OSPF)
- maximum redistributed-prefixes (OSPF)
- message-digest-key
- mpls ldp auto-config (OSPF)
- mpls ldp sync (OSPF)
- mpls ldp sync-igp-shortcuts
- mpls traffic-eng (OSPF)
- mpls traffic-eng igp-intact (OSPF)
- mpls traffic-eng multicast-intact (OSPF)
- mpls traffic-eng router-id (OSPF)
- mtu-ignore (OSPF)
- multi-area-interface
- neighbor (OSPF)
- neighbor database-filter all out
- network (OSPF)
- nsf (OSPF)
- nsf flush-delay-time (OSPF)
- nsf interval (OSPF)
- nsf lifetime (OSPF)
- nsr (OSPF)
- nssa (OSPF)
- ospf name-lookup
- packet-size (OSPF)
- passive (OSPF)
- priority (OSPF)
- protocol shutdown
- queue dispatch flush-lsa
- queue dispatch incoming
- queue dispatch rate-limited-lsa
- queue dispatch spf-lsa-limit
- queue limit
- range (OSPF)
- redistribute (OSPF)
- retransmit-interval (OSPF)
- route-policy (OSPF)
- router-id (OSPF)
- router ospf
- security ttl (OSPF)
- sham-link
- show ospf
- show ospf border-routers
- show ospf database
- show ospf flood-list
- show ospf interface
- show ospf mpls traffic-eng
- show ospf message-queue
- show ospf neighbor
- show ospf request-list
- show ospf retransmission-list
- show ospf routes
- show ospf sham-links
- show ospf statistics interface
- show ospf summary-prefix
- show ospf virtual-links
- show protocols (OSPF)
- snmp trap rate-limit
- spf prefix-priority (OSPF)
- stub (OSPF)
- summary-prefix (OSPF)
- timers lsa group-pacing
- timers lsa min-arrival
- timers lsa refresh
- timers throttle lsa all (OSPF)
- timers throttle spf (OSPF)
- transmit-delay (OSPF)
- virtual-link (OSPF)
- vrf (OSPF)
address-family (OSPF)
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.
Syntax Description
ipv4
Specifies IP Version 4 (IPv4) address prefixes.
unicast
(Optional) Specifies unicast address prefixes.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
adjacency stagger
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
area (OSPF)
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.
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 0/2/0/0authentication (OSPF)
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.
Syntax Description
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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area interface configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 mykey1The 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 mykeychainauthentication-key (OSPF)
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.
Syntax Description
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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
auto-cost (OSPF)
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.
Syntax Description
reference-bandwidth mbps
Specifies a rate in Mbps (bandwidth). Range is 1 to 4294967.
disable
Assigns a cost based on interface type.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 1000capability opaque disable
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
clear ospf process
To reset an Open Shortest Path First (OSPF) router process without stopping and restarting it, use the clear ospf process command in EXEC mode.
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
The vrf keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to reset all OSPF processes:
RP/0/0/CPU0:router# clear ospf processThe following example shows how to reset the OSPF 1 process:
RP/0/0/CPU0:router# clear ospf 1 processclear ospf redistribution
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 mode.
Syntax Description
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.
Command History
Release
Modification
Release 2.0
This command was introduced.
Release 3.3.0
The vrf keyword was added.
Command History
Release
Modification
Release 3.2
This command was introduced .
Release 3.3.0
The vrf keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
clear ospf routes
To clear all Open Shortest Path First (OSPF) routes from the OSPF routing table, use the clear ospf routes command in EXEC mode.
Syntax Description
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
clear ospf statistics
To clear the Open Shortest Path First (OSPF) statistics of neighbor state transitions, use the clear ospf statistics command in EXEC mode.
clear ospf [ process-name [ vrf { vrf-name | all } ] ] statistics [ neighbor [ type interface-path-id ] [ip-address] ]
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
The vrf keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
clear ospf statistics interface
To clear the Open Shortest Path First (OSPF) statistics per interface, use the clear ospf statistics interface command in EXEC mode.
Syntax Description
type
Interface type. For more information, use the question mark (?) online help function.
interface-path-id
Physical interface or virtual interface.
Note 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 0/21/0/0cost (OSPF)
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.
Syntax Description
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 65cost-fallback (OSPF)
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.
Syntax Description
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.
Command Default
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 300database-filter all out (OSPF)
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.
Syntax Description
Command Modes
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
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
Examples
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 outdead-interval (OSPF)
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.
Syntax Description
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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 40default-cost (OSPF)
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.
Syntax Description
cost
Cost for the default summary route used for a stub or NSSA area. The acceptable value is a 24-bit number.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 0/4/0/3default-information originate (OSPF)
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 ]
no default-information originate
Syntax Description
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. 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
route-policy policy-name
(Optional) Specifies that a routing policy be used and the routing policy name.
Command Default
When you do not use this command in router configuration mode, no default external route is generated into an OSPF routing domain.
metric-value : 10
type-value : 2
Command History
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 .
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
For information about routing policies, see the Routing Policy Commands on Cisco IOS XR Softwaremodule of Cisco IOS XR Routing Command Reference.
Task ID
Examples
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 1default-metric (OSPF)
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.
Syntax Description
Command History
Release
Modification
Release 3.2
This command was introduced
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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_ispdemand-circuit (OSPF)
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.
Syntax Description
disable
(Optional) Disables the interface as an OSPF demand circuit.
enable
(Optional) Enables the interface as an OSPF demand circuit.
Command Default
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
disable-dn-bit-check
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
distance (OSPF)
To define an administrative distance, use the distance command in the appropriate 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]
Syntax Description
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.
Command Default
If this command is not specified, then the administrative distance is the default, as specified in Table 1.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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).
This table lists default administrative distances.
Table 1 Default Administrative DistancesRoute 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
Examples
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 0.0.0.255Related Commands
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.
distance ospf
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 200distribute-list
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 ] }
no distribute-list access-list-name { in | out }
Syntax Description
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 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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
Task ID
Examples
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 0/1/0/3domain-id
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
Syntax Description
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).
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
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
Cisco IOS XR uses the OSPF Process ID as the default Domain ID value. However, when you peer an IOS XR router with an IOS router, the two Domain IDs must match. Therefore, you must manually configure the IOS XR Domain ID value to match the IOS default Domain ID value. When these Domain IDs match, the routes have route code "O" because they are learned as intra-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 that value using the domain-id command.
Task ID
domain-tag
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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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).
Task ID
flood-reduction (OSPF)
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.
Syntax Description
enable
(Optional) Turns on this functionality at a specific level.
disable
(Optional) Turns off this functionality at a specific level.
Command Default
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added in the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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-reductionhello-interval (OSPF)
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.
Syntax Description
seconds
Interval (in seconds). The value must be the same for all nodes on a specific network. Range is 1 to 65535.
Command Default
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 (nonbroadcast).
Command Modes
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 15ignore lsa mospf
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 the appropriate mode. To restore the sending of syslog messages, use the no form of this command.
Command Default
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
fast-reroute per-link
To enable or disable the IP fast reroute (IPFRR) per-link loop-free alternate (LFA) computation, use the fast-reroute per-link command in the appropriate OSPF configuration mode. To disable this feature, use the no form of this command.
Syntax Description
enable
Enables computation of per-link Loop Free Alternates
disable
Disables computation of per-link Loop Free Alternates
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following example shows how to enable per-link computation of Loop Free Alternates under interface POS0/3/0/0:
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)# int pos 0/3/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# fast-reroute per-link enableThe following example shows how to disable per-link computation of Loop Free Alternates under interface POS0/3/0/0:
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)# int pos 0/3/0/0 RP/0/0/CPU0:router(config-ospf-ar-if)# fast-reroute per-link disablefast-reroute per-link exclude interface
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
Syntax Description
type
Interface type. For more information, use the question mark (?) online help function.
interface-path-id
Physical interface or virtual interface.
Note 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following example shows how to exclude an interface from IPFRR LFA:
RP/0/0/CPU0:router(config)# router ospf 1 RP/0/0/CPU0:router(config-ospf-ar-if)# fast-reroute per-link exclude interface POS 0/3/2/1interface (OSPF)
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.
Syntax Description
type
Interface type. For more information, use the question mark (?) online help function.
interface-path-id
Physical interface or virtualinterface.
Note se 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.
Command Default
When you do not specify this command in configuration mode, OSPF routing for interfaces is not enabled.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 3/0/0/1log adjacency changes (OSPF)
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.
Syntax Description
detail
Provides all (DOWN, INIT, 2WAY, EXSTART, EXCHANGE, LOADING, FULL) adjacency state changes.
disable
Disables sending adjacency change messages.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The detail and disable keywords were changed from optional to required.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
loopback stub-network
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.
Syntax Description
enable (Optional) Enables advertising loopbacks as stub networks.
disable (Optional) Disables advertising loopbacks as stub networks.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 enableRelated Commands
Command
Description
show ospf interfaceDisplays Open Shortest Path First (OSPF) interface information.
max-lsa
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 ]
Syntax Description
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 .
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to configure the OSPF instance to accept 12000 nonself-generated LSAs in the global routing table, and 1000 nonself-generated LSAs in VRF V1.
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 1000The 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 0max-metric
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
Syntax Description
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
Note OSPF will not populate maximum metric on the router's generated LSAs, when the OSPF routing process is configured to support Nonstop Routing (NSR) or Nonstop Forwarding/Graceful restart (NSF/GR).
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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:
- During a router reload, you prefer that OSPF wait for BGP to converge before accepting transit traffic. If there are no alternative paths, the router still accepts transit traffic.
- A router is in critical condition (for example, it has a very high CPU load or does not have enough memory to store all LSAs or build the routing table).
- When you want to gracefully introduce or remove a router to or from the network.
- When you have a test router in a lab, connected to a production network.
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
Examples
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-bgpmaximum interfaces (OSPF)
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.
Syntax Description
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
maximum paths (OSPF)
To control the maximum number of parallel routes that the Open Shortest Path First (OSPF) protocol can support, use the maximum paths command in the appropriate 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.
Syntax Description
maximum
Maximum number of parallel routes that OSPF can install in a routing table. Range is 1 to 32.
Note The maximum limit imposed by the platform is 16
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
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.
Task ID
maximum redistributed-prefixes (OSPF)
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
Syntax Description
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.
Command Default
If the command is not specified, the default is 10000.
The threshold value defaults to 75 percent.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
message-digest-key
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.
Syntax Description
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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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 OLDYou change the configuration to the following:
interface GigabitEthernet 0/3/0/2 message-digest-key 101 md5 NEWThe 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 100Then, 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
Examples
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 8ry4222mpls ldp auto-config (OSPF)
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
mpls ldp sync (OSPF)
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
mpls ldp sync-igp-shortcuts
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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-shortcutsWhen 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 disablempls traffic-eng (OSPF)
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
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
Examples
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 0mpls traffic-eng igp-intact (OSPF)
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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-intactmpls traffic-eng multicast-intact (OSPF)
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 mode. To remove the MPLS TE area, use the no form of this command.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
Task ID
mpls traffic-eng router-id (OSPF)
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 mode. To disable this feature, use the no form of this command.
Syntax Description
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.
Command Default
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
Task ID
mtu-ignore (OSPF)
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.
Syntax Description
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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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-ignoremulti-area-interface
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.
Syntax Description
type
Interface type. For more information, use the question mark (?) online help function.
interface-path-id
Physical interface or virtual interface.
Note 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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)#neighbor (OSPF)
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 ]
Syntax Description
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.
Command Default
No configuration is specified.
priority number : 0
poll-interval seconds : 120 seconds (2 minutes)
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 180The 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 180neighbor database-filter all out
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.
Syntax Description
Command Default
Instead of all outgoing LSAs being filtered to the neighbor, they are flooded to the neighbor.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 outnetwork (OSPF)
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
Syntax Description
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.
Command Default
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.
Command History
Release
Modification
Release 3.2
This command was introduced
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 180nsf (OSPF)
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 ] }
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
nsf flush-delay-time (OSPF)
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.
Syntax Description
seconds
Length of time (in seconds) allowed for NSF external route queries. Range is 1 to 3600 seconds.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
nsf interval (OSPF)
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.
Syntax Description
seconds
Length of time (in seconds) between consecutive restart attempts. Range is 90 to 3600 seconds.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
nsf lifetime (OSPF)
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.
Syntax Description
seconds
The length of time (in seconds) that routes are held in the RIB. Range is 90 to 3600 seconds.
Command History
Release
Modification
Release 3.2
This command was introduced
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
nsr (OSPF)
To configure nonstop routing (NSR) for the Open Shortest Path First (OSPF) protocol, use the nsr command in OSPF router 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The NSR feature allows an OSPF process on the active RP to synchronize all necessary data and states with the OSPF process on the standby RP. When the switchover happens, the OSPF process on the newly active RP has all the necessary data and states to continue running and does not require any help from its neighbors.
Task ID
nssa (OSPF)
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
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
Added metric and metric-type keywords.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
ospf name-lookup
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
packet-size (OSPF)
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 mode. To disable this function and reestablish the default packet size, use the no form of this command.
Syntax Description
Command Default
IIf command is not specified, the default packet size is the minimum of the interface IP MTU size or 9000 bytes.
Command Modes
Router configuration
Area configuration
Interface configuration
VRF configuration
Multi-area configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
Task ID
Examples
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 3500passive (OSPF)
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.
Syntax Description
Command Default
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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)# endpriority (OSPF)
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.
Syntax Description
Command Default
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 6RP/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 4protocol shutdown
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 router configuration mode. To reenable the OSPF protocol, use the no form of this command.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
queue dispatch flush-lsa
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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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 30Use the show ospf message-queue command to see the queue dispatch values, peak lengths, and limits.
Related Commands
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.
queue dispatch incoming
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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following example shows how limit the number of incoming packets processed to 500:
RP/0/0/CPU0:router(config-ospf)# queue dispatch incoming 500Use the show ospf message-queue command to see the queue dispatch values, peak lengths, and limits.
Related Commands
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.
queue dispatch rate-limited-lsa
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.
Syntax Description
Command Default
The default number of rate-limited LSAs processed per run is 300 (when this count is not configured).
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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 300Related Commands
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.
queue dispatch spf-lsa-limit
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.
Syntax Description
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.
Command Default
The default number of Type 3-4 and Type 5-7 processed per run is 150 LSAs (when this command is not configured).
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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 100Related Commands
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.
queue limit
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.
Syntax Description
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.
Command Default
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).
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 9000Related Commands
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.
range (OSPF)
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 ]
Syntax Description
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.
Command Default
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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)# endredistribute (OSPF)
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.
Border Gateway Protocol (BGP)
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 ]
Local Interface Routes
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 ]
Directed-attached gateway redundancy (DAGR)
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 ]
Enhanced Interior Gateway Routing Protocol (EIGRP)
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 ]
Intermediate System-to-Intermediate System (IS-IS)
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 ]
Open Shortest Path First (OSPF)
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 ]
Routing Information Protocol (RIP)
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 ]
IP Static Routes
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 ]
Syntax Description
Command Default
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.
Command History
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
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 100The 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 100In 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 0/1/0/1retransmit-interval (OSPF)
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.
Syntax Description
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.
Command Default
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.
Command Modes
Interface configuration
Area configuration
Router configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 8route-policy (OSPF)
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.
Syntax Description
route-policy-name
Name of route policy.
in
Applies policy to inbound routes.
out
Applies policy to outbound routes.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
router-id (OSPF)
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.
Syntax Description
Command Default
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 172.20.10.10router ospf
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.
Syntax Description
process-name
Name that uniquely identifies an OSPF routing process. The process name is any alphanumeric string no longer than 40 characters without spaces.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 109security ttl (OSPF)
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.
Syntax Description
Command History
Release
Modification
Release 3.5.0
This command was introduced.
Release 3.6.0
The disable keyword was removed.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 2sham-link
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to configure an OSPF sham link:
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 23show ospf
To display general information about Open Shortest Path First (OSPF) routing processes, use the show ospf command in EXEC mode.
Syntax Description
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 values of the vrf-names argument.
all
(Optional) Specifies all OSPF VRF instances.
summary
(Optional) Displays OSPF summary information.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 2 show ospf Field DescriptionsField
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.
show ospf border-routers
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.
Syntax Description
process-name
(Optional) OSPF process name. 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.
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 POS 3/0/0/0, ABR/ASBR , Area 0, SPF 3
This table describes the significant fields shown in the display.
Table 3 show ospf border-routers Field DescriptionsField
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.
show ospf database
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]
Syntax Description
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The internal keyword was added.
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 4 show ospf database Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 5 show ospf database asbr-summary Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 6 show ospf database external Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 7 show ospf database network Field DescriptionsField
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 : 1The 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
This table describes the significant fields shown in the display.
Table 8 show ospf database opaque-area Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 9 show ospf database router Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 10 show ospf database summary Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 11 show ospf database database-summary Field DescriptionsField
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.
show ospf flood-list
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.
Syntax Description
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.
Note 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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 12 show ospf flood-list Field DescriptionsField
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.
show ospf interface
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 ]
Syntax Description
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following is sample output from the show ospf interface command:
RP/0/0/CPU0:router# show ospf interface GigabitEthernet0/2/0/1 is up, line protocol is up Internet Address 121.10.10.2/24, Area 2 Process ID 1, Router ID 200.2.2.2, Network Type POINT_TO_POINT, Cost: 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 Index 1/3, flood queue length 0 Next 0(0)/0(0) Last flood scan length is 3, maximum is 10 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 101.3.3.3 Suppress hello for 0 neighbor(s) Multi-area interface Count is 1 Multi-Area interface exist in area 1 Neighbor Count is 1 GigabitEthernet0/3/0/0 is up, line protocol is up Internet Address 145.10.10.2/16, Area 3 Process ID 1, Router ID 200.2.2.2, Network Type POINT_TO_POINT, Cost: 1 Transmit Delay is 1 sec, State POINT_TO_POINT, BFD enabled, BFD interval 15 msec, BFD multiplier 3 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Index 1/5, flood queue length 0 Next 0(0)/0(0) Last flood scan length is 3, maximum is 11 Last flood scan time is 0 msec, maximum is 1 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 101.3.3.3 Suppress hello for 0 neighbor(s) Message digest authentication enabled Youngest key id is 1 Multi-area interface Count is 0The following is sample output when MPLS LDP Sync is configured on the OSPF routing process and MPLS LDP is configured on Packet-over-SONET/SDH (POS) interface 0/2/0/1:
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#
This table describes the significant fields shown in the display.
Table 13 show ospf interface Field DescriptionsField
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.
show ospf mpls traffic-eng
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 }
Syntax Description
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.
Note 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.
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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
This table describes the significant fields shown in the display.
Table 14 show ospf mpls traffic-eng link Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 15 show ospf mpls traffic-eng fragment Field DescriptionsField
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.
show ospf message-queue
To display the information about the queue dispatch values, peak lengths, and limits, use the show ospf message-queue command in EXEC mode.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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
This table describes the significant fields shown in the display.
Table 16 show ospf message-queue Field DescriptionsField
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.
Related Commands
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.
show ospf neighbor
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 ]
Syntax Description
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.
interface-path-id
Physical interface or virtual interface.
Note 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) Neighbor ID.
detail
(Optional) Displays all neighbors given in detail (lists all neighbors).
area-sorted
(Optional) Specifies that all neighbors are grouped by area.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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
This table describes the significant fields shown in the display.
Table 17 show ospf neighbor Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 18 show ospf neighbor 192.168.199.137 Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 19 show ospf neighbor GigabitEthernet 0/3/0/2 192.168.199.137 Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 20 show ospf neighbor GigabitEthernet 0/3/0/3 Field DescriptionsField
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
This table describes the significant fields shown in the display.
Table 21 show ospf neighbor detail Field DescriptionsField
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.
show ospf request-list
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]
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 22 show ospf request-list 10.0.124.4 GigabitEthernet3/0/0/0 Field DescriptionsField
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.
show ospf retransmission-list
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]
Syntax Description
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.
interface-path-id
Physical interface or virtual interface.
Note 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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 23 show ospf retransmission-list 10.0.124.4 GigabitEthernet3/0/0/0 Field DescriptionsField
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.
show ospf routes
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]
Syntax Description
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.
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.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Use the show ospf route 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
Examples
The following is sample output from the show ospf route command:
RP/0/0/CPU0:router# show ospf route 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
This table describes the significant fields shown in the display.
Table 24 show ospf route Field DescriptionsField
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 route command with a process name of 100:
RP/0/0/CPU0:router# show ospf 100 route 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
This table describes the significant fields shown in the display.
Table 25 show ospf 100 routeField DescriptionsField
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 route command with a prefix of 10.0.0.0 and a length of 24:
RP/0/0/CPU0:router# show ospf route 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
This table describes the significant fields shown in the display.
Table 26 show ospf route 10.0.0.0/24Field DescriptionsField
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.
show ospf sham-links
To display Open Shortest Path First (OSPF) sham-link information, use the show ospf sham-links command in EXEC mode.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 27 show ospf sham-links Field DescriptionsField
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.
show ospf statistics interface
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 ]
Syntax Description
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
(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.
summary-only
(Optional) Displays only the summary statistics for the given instance or area (if specified).
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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
This table describes the significant fields shown in the display.
Table 28 show ospf statistics interface Field DescriptionsField
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.
show ospf summary-prefix
To display Open Shortest Path First (OSPF) aggregated summary address information, use the show ospf summary-prefix command in EXEC mode.
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 29 show ospf summary-prefix Field DescriptionsField
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.
show ospf virtual-links
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.
Syntax Description
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.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.6.0
The all keyword was added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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
This table describes the significant fields shown in the display.
Table 30 show ospf virtual-links Field DescriptionsField
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.
show protocols (OSPF)
To display information about the OSPFv2 processes running on the router, use the show protocols command in EXEC mode.
Syntax Description
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:
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
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
This table describes the significant fields shown in the display.
Table 31 show protocols ospf Field DescriptionsField
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).
snmp trap rate-limit
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.
Syntax Description
window-size Specifies the trap rate limit sliding window size.
max-num-traps Specifies the maximum number of traps sent in window time.
Command History
Release Modification Release 3.9.0 This command was introduced. This command replaces the snmp-server trap ospf rate-limit command.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
spf prefix-priority (OSPF)
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.
Syntax Description
route-policy policy-name
Specifies the route policy to apply to OSPFv2 prefix prioritization.
Note If SPF prefix prioritization is configured, /32 prefixes are no longer preferred by default. To retain the /32 prefixes in higher-priority queues, define the route-policy accordingly.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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-setTask ID
Examples
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-prioritystub (OSPF)
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.
Syntax Description
no-summary
(Optional) Prevents an Area Border Router (ABR) from sending summary link advertisements into the stub area.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 0/3/0/3summary-prefix (OSPF)
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.
Syntax Description
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.
Command Default
When this command is not used, specific addresses are created for each route from another route source being distributed into the OSPF protocol.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 10.1.0.0 255.255.0.0timers lsa group-pacing
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.
Syntax Description
seconds
Interval (in seconds) at which LSAs are grouped and refreshed, checksummed, or aged. Range is 10 seconds to 1800 seconds.
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
timers lsa min-arrival
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
Syntax Description
milliseconds
Minimum interval (in milliseconds) between accepting same LSA.
Range is 0 to 600000 milliseconds.
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
timers lsa refresh
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.
Syntax Description
seconds
How often self-originated LSAs should be refreshed, in seconds. Range is 1800 to 2700 seconds.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 1800Related Commands
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.
timers throttle lsa all (OSPF)
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
Syntax Description
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.
Command Default
start-interval : 50 milliseconds
hold-interval : 200 milliseconds
max-interval : 5000 milliseconds
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 90000The 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 0timers throttle spf (OSPF)
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.
Syntax Description
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.
Command Default
spf-start:50 milliseconds
spf-hold: 200 milliseconds
spf-max-wait: 5000 milliseconds
Command History
Release
Modification
Release 3.2
This command was introduced.
Release 3.3.0
This command was added under the VRF configuration mode.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
transmit-delay (OSPF)
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.
Syntax Description
Command Modes
Router configuration
Area configuration
Interface configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configuration
Command History
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.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 3virtual-link (OSPF)
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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 mykeyvrf (OSPF)
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.
Syntax Description
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
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)# interface GigabitEthernet 0/2/0/01 This command is supported only in the default VRF mode.2 This command is supported only in the default VRF mode.3 This command is supported only in the default VRF mode.
