OSPF Commands on Cisco IOS XR Software
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Table Of Contents
OSPF Commands on Cisco IOS XR Software
database-filter all out (OSPF)
default-information originate (OSPF)
maximum redistributed-prefixes (OSPF)
mpls traffic-eng igp-intact (OSPF)
mpls traffic-eng multicast-intact (OSPF)
mpls traffic-eng router-id (OSPF)
neighbor database-filter all out
timers throttle lsa all (OSPF)
OSPF Commands on Cisco IOS XR Software
This chapter 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 configuration guide.
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.
address-family ipv4 [unicast]
no address-family ipv4 [unicast]
Syntax Description
ipv4
Specifies IP Version 4 (IPv4) address prefixes.
unicast
(Optional) Specifies unicast address prefixes.
Defaults
An address family is not specified.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
OSPF version 2 automatically provides routing services for IPv4 unicast topologies, so this command is redundant.
Task ID
Examples
The following example shows how to configure the OSPF router process with IPv4 unicast address prefixes:
RP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# address-family ipv4 unicastarea (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.
area area-id
no area area-id
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.
Defaults
No OSPF area is defined.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 Packet-over-SONET/SDH (POS) interface 0/2/0/0. POS interface 0/2/0/0 is bound to area 0 automatically.
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 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.
authentication [message-digest [keychain keychain] | null]
no authentication
Syntax Description
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# router-id 10.1.1.1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# authenticationRP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# authentication-key mykeyRP/0/RP0/CPU0:router(config-ospf-ar-if)# exitRP/0/RP0/CPU0:router(config-ospf)# area 1RP/0/RP0/CPU0:router(config-ospf-ar)# authenticationRP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/0RP/0/RP0/CPU0:router(config-ospf-ar-if)# authentication-key mykey1The following example shows how to configure use of an authentication keychain:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# router-id 10.1.1.1RP/0/RP0/CPU0:router(config-ospf)# authentication message-digest keychain mykeychainRelated Commands
Assigns a password to be used by neighboring routers that are using the simple password authentication of OSPF.
Specifies a key used with OSPF MD5 authentication.
authentication-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.
authentication-key [clear | encrypted] password
no authentication-key
Syntax Description
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Task ID
Examples
The following example shows how to configure an authentication password as the string yourpass:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# authentication-key yourpassRelated Commands
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.
auto-cost {reference-bandwidth mbps | disable}
no auto-cost {reference-bandwidth | disable}
Syntax Description
reference-bandwidth mbps
Specifies a rate in Mbps (bandwidth). Range is 1 to 4294967.
disable
Assigns a cost based on interface type.
Defaults
mbps: 100 Mbps
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# auto-cost reference-bandwidth 1000Related Commands
Explicitly specifies the cost of the interface (network) for OSPF path calculation.
capability 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.
capability opaque disable
no capability opaque disable
Command Default
Opaque LSAs are allowed.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to prevent OSPF from supporting opaque services:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# capability opaque disableclear 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.
clear ospf [process-name [vrf {vrf-name | all}]] process
Syntax Description
Defaults
No default behavior or value
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Task ID
Examples
The following example shows how to reset all OSPF processes:
RP/0/RP0/CPU0:router# clear ospf processThe following example shows how to reset the OSPF process 1:
RP/0/RP0/CPU0:router# clear ospf 1 processRelated Commands
Configures an OSPF routing process.
Configures a router ID for the OSPF process.
clear 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.
clear ospf [process-name [vrf {vrf-name | all}]] redistribution
Syntax Description
Defaults
No default behavior or value
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Task ID
Examples
The following example shows how to clear all redistributed routes across all processes from other protocols:
RP/0/RP0/CPU0:router# clear ospf redistributionclear 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.
clear ospf [process-name [vrf {vrf-name | all}]] routes
Syntax Description
Defaults
No default behavior or value
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to clear all OSPF routes from the OSPF routing table and recompute valid routes. When the OSPF routing table is cleared, OSPF routes in the global routing table are also recalculated.
RP/0/RP0/CPU0:router# clear ospf routesRelated Commands
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 [interface-type interface-instance] [ip-address]]
Syntax Description
Defaults
No default behavior or value
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Use the clear ospf statistics command to reset OSPF counters. Reset is useful to detect changes in counter values.
Task ID
Examples
The following example shows how to reset the OSPF transition state counters for all neighbors on Packet-over-SONET/SDH (POS) interface 0/2/0/0:
RP/0/RP0/CPU0:router# clear ospf statistics neighbor POS 0/2/0/0Related Commands
cost (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.
cost cost
no cost
Syntax Description
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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:
10^8 / 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 Packet-over-SONET/SDH (POS) interface 0/1/0/1:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# cost 65Related Commands
cost-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.
cost-fallback cost threshold bandwidth
no cost-fallback
Syntax Description
Defaults
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 Modes
Interface configuration
Command History
Release 3.6.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)#router ospf 100RP/0/RP0/CPU0:router(config-ospf)#router-id 2.2.2.2RP/0/RP0/CPU0:router(config-ospf)#area 0RP/0/RP0/CPU0:router(config-ospf-ar)#interface bundle-pos1RP/0/RP0/CPU0:router(config-ospf-ar-if)#cost-fallback 1000 threshold 300Related Commands
Specifies the cost of the interface(network) for OSPF path calculation.
Controls how the OSPF protocol calculates default metrics for the interface.
database-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.
database-filter all out [disable | enable]
Syntax Description
Defaults
The database filter is disabled.
Command Modes
Interface configuration
Area configuration
Router configuration
VRF configuration
Multi-area configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 Packet-over-SONET/SDH (POS) interface 0/1/0/1:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# database-filter all outRelated Commands
dead-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.
dead-interval seconds
no dead-interval
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.
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# dead-interval 40Related Commands
Specifies the interval between hello packets that the Cisco IOS XR software sends on the interface.
default-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.
default-cost cost
no default-cost cost
Syntax Description
cost
Cost for the default summary route used for a stub or NSSA area. The acceptable value is a 24-bit number.
Defaults
cost: 1
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 Packet-over-SONET/SDH (POS) interface 0/4/0/3 is also configured in the stub area):
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# area 10.15.0.0RP/0/RP0/CPU0:router(config-ospf-ar)# stubRP/0/RP0/CPU0:router(config-ospf-ar)# default-cost 20RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/4/0/3Related Commands
default-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
Defaults
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: 2Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 Software module 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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# redistribute igrp 108 metric 100RP/0/RP0/CPU0:router(config-ospf)# default-information originate metric 100 metric-type 1Related Commands
default-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.
default-metric value
no default-metric value
Syntax Description
Defaults
Built-in, automatic metric translations, as appropriate for each routing protocol. Current metrics are displayed in the show ospf summary-prefix command output. Note that this output is only displayed if there are routes currently redistributed from protocols.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf# default-metric 10RP/0/RP0/CPU0:router(config-ospf)# redistribute isis 15Related Commands
Redistributes routes from one routing domain into a specified OSPF process.
Displays OSPF aggregated summary address information.
demand-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.
demand-circuit [disable | enable]
no demand-circuit
Syntax Description
disable
(Optional) Disables the interface as an OSPF demand circuit.
enable
(Optional) Enables the interface as an OSPF demand circuit.
Defaults
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 Modes
Interface configuration
Area configuration
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to set the configuration for an OSPF demand circuit:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# demand-circuitdisable-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.
disable-dn-bit-check
no disable-dn-bit-check
Syntax Description
This command has no arguments or keywords.
Defaults
Down bits are considered.
Command Modes
VRF configuration 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to specify that down bits be ignored:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# vrf v1RP/0/RP0/CPU0:router(config-ospf-vrf)# disable-dn-bit-checkdistance (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. Table 1 lists the default administrative distances.
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.
Defaults
If this command is not specified, then the administrative distance is the default, as specified in Table 1.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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).
Table 1 lists default administrative distances.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# distance 255RP/0/RP0/CPU0:router(config-ospf)# distance 90 192.168.40.0 0.0.0.255Related Commands
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.
distance ospf {intra-area | inter-area | external} distance
no distance ospf
Syntax Description
Defaults
distance: 110
Command Modes
Router configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# redistribute ospf 2RP/0/RP0/CPU0:router(config-ospf)# distance ospf external 200RP/0/RP0/CPU0:router(config-ospf)# exitRP/0/RP0/CPU0:router(config)# router ospf 2RP/0/RP0/CPU0:router(config-ospf)# redistribute ospf 1RP/0/RP0/CPU0:router(config-ospf)# distance ospf external 200Related Commands
distribute-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
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# ipv4 access-list 3RP/0/RP0/CPU0:router(config-ipv4-acl)# deny 172.17.10.0 0.0.0.255RP/0/RP0/CPU0:router(config-ipv4-acl)# permit any any!RP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# distribute-list 3 inRP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 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).
Defaults
No domain ID is specified.
Command Modes
VRF configuration 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Task ID
Examples
The following example shows how to specify a domain ID:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf o1RP/0/RP0/CPU0:router(config-ospf)# vrf v1RP/0/RP0/CPU0:router(config-ospf-vrf)# domain-id type 0105 value AABBCCDDEEFFdomain-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.
domain-tag tag
no domain-tag
Syntax Description
Defaults
No OSPF VRF domain tag is specified.
Command Modes
VRF configuration 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to specify the domain tag:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf o1RP/0/RP0/CPU0:router(config-ospf)# domain-tag 234flood-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.
flood-reduction [enable | disable]
no flood-reduction [enable | disable]
Syntax Description
enable
(Optional) Turns on this functionality at a specific level.
disable
(Optional) Turns off this functionality at a specific level.
Defaults
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 Modes
Interface configuration
Area configuration
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# flood-reductionRelated Commands
Displays OSPF-related interface information.
Displays OSPF neighbor information on an individual interface basis.
hello-interval (OSPF)
To specify the interval between hello packets that are sent on the Open Shortest Path First (OSPF) interface, use the hello-interval command in the appropriate mode. To return to the default time, use the no form of this command.
hello-interval seconds
no hello-interval
Syntax Description
seconds
Interval (in seconds). The value must be the same for all nodes on a specific network. Range is 1 to 65535.
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# hello-interval 15Related Commands
Sets the time period for which hello packets are suspended before neighbors declare the router down.
ignore 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.
ignore lsa mospf
no ignore lsa mospf
Syntax Description
This command has no arguments or keywords.
Defaults
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 Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure the router to suppress the sending of syslog messages when it receives MOSPF packets:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# ignore lsa mospfinterface (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 no form of this command.
interface type instance
no interface type instance
Syntax Description
Defaults
When you do not specify this command in configuration mode, OSPF routing for interfaces is not enabled.
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS4/0/0/3!RP/0/RP0/CPU0:router(config-ospf)# area 2RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/3!RP/0/RP0/CPU0:router(config-ospf)# area 3RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS3/0/0/2!RP/0/RP0/CPU0:router(config-ospf)# area 10.9.50.0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS3/0/0/1log 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.
log adjacency changes {detail | disable}
Syntax Description
detail
Provides all (DOWN, INIT, 2WAY, EXSTART, EXCHANGE, LOADING, FULL) adjacency state changes.
disable
Disables sending adjacency change messages.
Defaults
The router sends a syslog message when the state of an OSPF neighbor changes.
Command Modes
Router configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure the software to send a syslog message for any OSPF neighbor state changes:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# log adjacency changes enablemax-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
Defaults
Router LSAs are originated with normal link metrics.
overriding-metric:16711680Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Use the max-metric command to cause the software to originate router LSAs with router link metrics set to LSInfinity (0XFFFF). This feature can be useful in Internet backbone routers that run both OSPF and BGP because OSPF converges more quickly than BGP and may begin attracting traffic before BGP has converged, resulting in dropped traffic.
If this command is configured, the router advertises its locally generated router LSAs with a metric of 0XFFFF. This action allows the router to converge but not attract transit traffic if there are better, alternative paths around this router. After the specified announce-time value or notification from BGP has expired, the router advertises the local router LSAs with the normal metric (interface cost).
If this command is configured with the on-startup keyword, then the maximum metric is temporarily set only after reboot is initiated. If this command is configured without the on-startup keyword, then the maximum metric is permanently used until the configuration is removed.
If the include-stub keyword is enabled, the stub-links in the router LSA will be sent with the max-metric. If the summary-lsa keyword is enabled, all self-generated summary LSAs will have a metric set to 0xFF0000, unless the metric value is specified with the max-metric value parameter. If the external-lsa keyword is enabled, all self-generated external LSAs will have a metric set to 0xFF0000, unless the metric value is specified with the max-metric value parameter.
This command might be useful when you want to connect a router to an OSPF network, but do not want real traffic flowing through it if there are better, alternative paths. If there are no alternative paths, this router still accepts transit traffic as before.
Some cases where this command might be useful are as follows:
•
•
•
•
Note
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/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.
maximum interfaces number-interfaces
no maximum interfaces
Syntax Description
Defaults
If the command is not specified, the default is 255.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure a maximum interface limit of 700 on a router:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# maximum interfaces 700Related Commands
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.
maximum paths maximum
no maximum paths
Syntax Description
maximum
Maximum number of parallel routes that OSPF can install in a routing table. Range is 1 to 32 for Cisco CRS-1s and 1 to 16 for Cisco XR 12000 Series Routers.
Defaults
Cisco CRS-1s: 32 paths
Cisco XR 12000 Series Routers: 16 pathsCommand Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
When the maximum number of parallel routes is reduced, all existing paths are pruned and the new maximum number of paths are reinstalled. During this period, you may experience some packet loss for a few seconds.
Task ID
Examples
The following example shows how to allow a maximum of two paths to a destination:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# maximum paths 2maximum redistributed-prefixes (OSPF)
To limit the aggregate number of routes that may 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
Defaults
If the command is not specified, the default is 10000.
The threshold value defaults to 75 percent.Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Use the maximum redistributed-prefixes command to increase or decrease the maximum number of 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
Examples
The following example shows how to configure a maximum number of routes that can be redistributed for an OSPF routing process:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# maximum redistributed-prefixes 15000Related Commands
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.
message-digest-key key-id md5 {key | clear key | encrypted key}
no message-digest-key key-id
Syntax Description
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 POS 0/3/0/2message-digest-key 100 md5 OLDYou change the configuration to the following:
interface POS 0/3/0/2message-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 1no 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
Task ID
Examples
The following example shows how to set a new key 19 with the password 8ry4222:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# message-digest-key 19 md5 8ry4222Related Commands
Configures an OSPF area.
Enables plain text, MD5 authentication, or null authentication for an OSPF interface.
Enables authentication for an OSPF area.
mpls 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.
mpls ldp auto-config
no mpls ldp auto-config
Syntax Description
This command has no arguments or keywords.
Defaults
LDP-IGP interface automatic configuration is disabled for OSPF.
Command Modes
Interface configuration
Area configuration
Router configurationCommand History
Release 3.6.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to enable LDP-IGP interface automatic configuration:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf o1RP/0/RP0/CPU0:router(config-ospf)# mpls ldp auto-configmpls 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.
mpls ldp sync [disable]
no mpls ldp sync
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.
Defaults
LDP-IGP synchronization is disabled for OSPF.
Command Modes
Interface configuration
Area configuration
Router configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to enable LDP-IGP synchronization:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf o1RP/0/RP0/CPU0:router(config-ospf)# mpls ldp syncmpls 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 mode. To remove the MPLS TE from an area, use the no form of this command.
mpls traffic-eng
no mpls traffic-eng
Note
Syntax Description
This command has no arguments or keywords.
Defaults
MPLS TE is not configured for OSPF.
Command Modes
Area configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# router-id 10.10.10.10RP/0/RP0/CPU0:router(config-ospf)# mpls traffic-eng router-id loopback 0RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf)# mpls traffic-engRP/0/RP0/CPU0:router(config-ospf-ar)# interface loopback 0Related Commands
mpls 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.
mpls traffic-eng igp-intact
no mpls traffic-eng igp-intact
Syntax Description
This command has no arguments or keywords.
Defaults
IGP-intact is disabled.
Command Modes
Router configuration
Command History
Release 3.7.0
This command was introduced on the Cisco CRS-1 and the Cisco XR 12000 Series Router.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# mpls traffic-eng igp-intactRelated Commands
Configures the maximum number of parallel routes that the Open Shortest Path First (OSPF) protocol can support.
mpls traffic-eng multicast-intact (OSPF)
To configure an Open Shortest Path First (OSPF) 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.
mpls traffic-eng multicast-intact
no mpls traffic-eng multicast-intact
Note
Syntax Description
This command has no arguments or keywords.
Defaults
MPLS TE is not configured for OSPF.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 enable publishing of multicast-intact paths to RIB:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# mpls traffic-eng multicast-intactmpls 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.
mpls traffic-eng router-id {router-id | interface-type interface-instance}
no mpls traffic-eng router-id {router-id | interface-type interface-number}
Note
Syntax Description
Defaults
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 Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Task ID
Examples
The following example shows how to specify the traffic engineering router identifier as the IP address associated with loopback interface 0:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# mpls traffic-eng router-id loopback 0Related Commands
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.
mtu-ignore [disable | enable]
no mtu-ignore
Syntax Description
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/3RP/0/RP0/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.
multi-area-interface type instance
no multi-area-interface type instance
Syntax Description
Defaults
An OSPF network is enabled for one area only.
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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.
Note
Task ID
Examples
The following example shows how to enable multiple area adjacency for OSPF 109:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# area 1RP/0/RP0/CPU0:router(config-ospf-ar)# multi-area-interface POS 0/1/0/3RP/0/RP0/CPU0:router(config-ospf-ar-mif)# ?authentication Enable authenticationauthentication-key Authentication password (key)commit Commit the configuration changes to runningcost Interface costdatabase-filter Filter OSPF LSA during synchronization and floodingdead-interval Interval after which a neighbor is declared deaddescribe Describe a command without taking real actionsdistribute-list Filter networks in routing updatesdo Run an exec commandexit Exit from this submodehello-interval Time between HELLO packetsmessage-digest-key Message digest authentication password (key)mtu-ignore Enable/Disable ignoring of MTU in DBD packetsno Negate a command or set its defaultspacket-size Customize size of OSPF packets upto MTUpwd Commands used to reach current submoderetransmit-interval Time between retransmitting lost link state advertisementsroot Exit to the global configuration modeshow Show contents of configurationtransmit-delay Estimated time needed to send link-state update packetRP/0/RP0/CPU0:P1_CRS-8(config-ospf-ar-mif)#Related Commands
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
Defaults
No configuration is specified.
priority number: 0
poll-interval seconds: 120 seconds (2 minutes)Command Modes
Interface configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/0/0/0:router(config-ospf-ar-if)# neighbor 172.16.3.4 priority 1 poll-interval 180The following example illustrates a network with nonbroadcast:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# interface POS1/0/0/3RP/0/RP0/CPU0:router(config-if)# ip address 172.16.3.10 255.255.255.0RP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS1/0/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# network nonbroadcastRP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.4 priority 1 poll-interval 180RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.5 cost 10 priority 1 poll-interval 180RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.6 cost 15 priority 1 poll-interval 180RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.7 priority 1 poll-interval 180Related Commands
neighbor 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.
neighbor ip-address database-filter all out
no neighbor ip-address database-filter all out
Syntax Description
Defaults
Instead of all outgoing LSAs being filtered to the neighbor, they are flooded to the neighbor.
Command Modes
Interface configuration
Command History
f
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS1/0/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 10.2.3.4 database-filter all outRelated Commands
network (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
Defaults
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 GigE and TenGigE interfaces default to broadcast.Command Modes
Interface configuration
Area configuration
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# network non-broadcastRP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 172.16.3.4 priority 1 poll-interval 180Related Commands
nsf (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
Defaults
NSF is disabled.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to cancel NSF restart for the entire OSPF process if non-NSF neighbors are detected on any network interface during restart:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# nsf cisco enforce globalnsf 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.
nsf flush-delay-time seconds
no nsf flush-delay-time seconds
Syntax Description
seconds
Length of time (in seconds) allowed for NSF external route queries. Range is 1 to 3600 seconds.
Defaults
seconds: 300
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to configure the maximum time for NSF to learn external routes for OSPF at 60 seconds:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# nsf flush-delay-time 60nsf interval (OSPF)
To configure the minimum time between nonstop forwarding (NSF) restart attempts for the Open Shortest Path First (OSPF) protocol, use the nsf interval command in the appropriate mode. To remove this command from the configuration file and restore the system to its default condition, use the no form of this command.
nsf interval seconds
no nsf interval seconds
Syntax Description
Defaults
seconds: 90
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure the minimum time between NSF restart attempts at 120 seconds:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# nsf interval 120nsf 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.
nsf lifetime seconds
no nsf lifetime seconds
Syntax Description
seconds
The length of time (in seconds) that routes are held in the RIB. Range is 90 to 3600 seconds.
Defaults
seconds: 95
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure the maximum lifetime for OSPF NSF at 120 seconds:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# nsf lifetime 120nsr (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.
nsr
no nsr
Syntax Description
This command has no arguments or keywords.
Defaults
NSR is not defined.
Command Modes
Router configuration
Command History
Release 3.6.0
This command was introduced on the Cisco CRS-1.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
The NSR feature allows an OSPF process on the active RP to syncronize 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
Examples
The following example shows how to configure NSR:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# nsrnssa (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
Defaults
No NSSA area is defined.
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure area 1 as an NSSA area:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 1RP/0/RP0/CPU0:router(config-ospf-ar)# nssaospf 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.
ospf name-lookup
no ospf name-lookup
Syntax Description
This command has no arguments or keywords.
Defaults
Routers are displayed by router ID or neighbor ID.
Command Modes
Global configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to configure OSPF to identify a router by name:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# ospf name-lookuppacket-size
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.
packet-size bytes
no packet-size
Syntax Description
Defaults
If command is not specified, the default packet size is 1500 bytes.
Command Modes
Router configuration
Area configuration
Interface configuration
VRF configuration
Multi-area configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS1/0/0/2RP/0/RP0/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.
passive [disable | enable]
no passive
Syntax Description
Defaults
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 Modes
Interface configuration
Area configuration
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 Packet-over-SONET/SDH (POS) interface 1/0/0/2 reduces OSPF updates because passive mode is enabled; however, POS interface 0/1/0/3 receives normal OSPF traffic flow:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS1/0/0/2RP/0/RP0/CPU0:router(config-ospf-ar-if)# passiveRP/0/RP0/CPU0:router(config-ospf-ar-if)# exitRP/0/RP0/CPU0:router(config-ospf-ar)# interface POS1/0/0/3RP/0/RP0/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.
priority value
no priority value
Syntax Description
Defaults
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 Modes
Interface configuration
Area configuration
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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:
Router A
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-if)# ipv4 address 10.0.0.2 255.255.255.0RP/0/RP0/CPU0:router(config-if)# exitRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# network non-broadcastRP/0/RP0/CPU0:router(config-ospf-ar-if)# priority 4RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 10.0.0.1 priority 6Router B
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# interface POS 0/2/0/1RP/0/RP0/CPU0:router(config-if)# ipv4 address 10.0.0.1 255.255.255.0RP/0/RP0/CPU0:router(config-if)# exitRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/2/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# network non-broadcastRP/0/RP0/CPU0:router(config-ospf-ar-if)# priority 6RP/0/RP0/CPU0:router(config-ospf-ar-if)# neighbor 10.0.0.2 priority 4Related Commands
Configures OSPF routers interconnecting to nonbroadcast networks.
Configures the OSPF network type to a type other than the default for a given medium.
protocol 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.
protocol shutdown
no protocol shutdown
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values
Command Modes
Router configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to disable the OSPF 1 instance:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# protocol shutdownrange (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
Defaults
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 Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS 0/3/0/2!RP/0/RP0/CPU0:router(config-ospf)# area 36.0.0.0RP/0/RP0/CPU0:router(config-ospf-ar)# range 10.31.0.0 255.255.0.0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS0/1/0/0RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/1/0/0RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/1/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/1/0/2RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/1/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/2/0/0RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/2/0/1RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/2/0/2RP/0/RP0/CPU0:router(config-ospf-ar-if)# interface POS0/2/0/3RP/0/RP0/CPU0:router(config-ospf-ar-if)# endRelated Commands
Creates aggregate addresses for routes being redistributed from another routing protocol into the OSPF protocol.
redistribute (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 [metric metric-value] [metric-type {1 | 2}] [route-policy policy-name] [tag tag-value]
no redistribute connected [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
Defaults
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 routeCommand Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Note
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 Cisco IOS XR Software module of Cisco IOS XR Routing Command Reference.
OSPF Considerations
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 110RP/0/RP0/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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# interface POS 0/1/0/1RP/0/RP0/CPU0:router(config-if)# ip address 10.0.0.0 255.0.0.0!RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/2RP/0/RP0/CPU0:router(config)# ip address 10.99.0.0 255.0.0.0!RP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# redistribute ospf 2RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/2/0/2!RP/0/RP0/CPU0:router(config)# router ospf 2RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/1/0/1Related Commands
retransmit-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.
retransmit-interval seconds
no retransmit-interval
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.
Defaults
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 configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/2/0/1RP/0/RP0/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.
route-policy route-policy-name {in | out}
no route-policy route-policy-name {in | out}
Syntax Description
route-policy-name
Name of route policy.
in
Applies policy to inbound routes.
out
Applies policy to outbound routes.
Defaults
No policy is applied.
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Examples
The following example shows how to specify an OSPF route policy for inbound routes in area 0:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-area)# route-policy area0_in inrouter-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.
router-id {router-id}
no router-id {router-id}
Syntax Description
Defaults
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 Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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.
OSPF attempts to obtain a router ID in the following ways (in order of preference):
1.
2.
3.
4.
Note
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config-ospf)# router-id 172.20.10.10Related Commands
Resets an OSPF router process without stopping and restarting it.
ipv4 address
Sets a primary IPv4 address for an interface.
router 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.
router ospf process-name
no router ospf process-name
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.
Defaults
No OSPF routing process is defined.
Command Modes
Global configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
You can specify multiple OSPF routing processes in each router.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109Related Commands
security 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.
security ttl [hops hops-number]
no security ttl
Syntax Description
Defaults
hops-number: 1
Command Modes
Router configuration
Area configuration
Interface configurationCommand History
Release 3.5.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.6.0
The disable keyword was removed.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface GigabitEthernet0/6/0/3RP/0/RP0/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.
sham-link source-address destination-address
no sham-link source-address destination-address
Syntax Description
Defaults
No sham link is configured.
Command Modes
VRF area configuration
Command History
Release 3.6.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 109RP/0/RP0/CPU0:router(config_ospf)# vrf vrf_aRP/0/RP0/CPU0:router(config_ospf_vrf)# area 0RP/0/RP0/CPU0:router(config_ospf_vrf_ar)# sham-link 192.168.40.0 172.16.30.0RP/0/RP0/CPU0:router(config_ospf_vrf_ar_sl)# cost 23Related Commands
Configures an OSPF area.
Explicitly specifies the cost of the interface (network) for OSPF path calculation.
Configures an OSPF VPN routing and forwarding (VRF) instance.
show ospf
To display general information about Open Shortest Path First (OSPF) routing processes, use the show ospf command in EXEC mode.
show ospf [process-name] [vrf {vrf-name | all}] [summary]
Syntax Description
Defaults
IPv4 and unicast address prefixes
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospfRouting Process "ospf 1" with ID 1.1.1.1Supports only single TOS(TOS0) routesSupports opaque LSAIt is an area border routerInitial SPF schedule delay 5000 msecsMinimum hold time between two consecutive SPFs 10000 msecsMaximum wait time between two consecutive SPFs 10000 msecsInitial LSA throttle delay 500 msecsMinimum hold time for LSA throttle 5000 msecsMaximum wait time for LSA throttle 5000 msecsMinimum LSA interval 5000 msecs. Minimum LSA arrival 1 secsMaximum number of configured interfaces 255Number of external LSA 0. Checksum Sum 00000000Number of opaque AS LSA 0. Checksum Sum 00000000Number of DCbitless external and opaque AS LSA 0Number of DoNotAge external and opaque AS LSA 0Number of areas in this router is 2. 2 normal 0 stub 0 nssaExternal flood list length 0Non-Stop Forwarding enabledArea BACKBONE(0) (Inactive)Number of interfaces in this area is 2SPF algorithm executed 8 timesNumber of LSA 2. Checksum Sum 0x01ba83Number of opaque link LSA 0. Checksum Sum 00000000Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 0Area 1Number of interfaces in this area is 1SPF algorithm executed 9 timesNumber of LSA 2. Checksum Sum 0x0153eaNumber of opaque link LSA 0. Checksum Sum 00000000Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 0Table 2 describes the significant fields shown in the display.
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.
show ospf [process-name] [vrf {vrf-name | all}] border-routers [router-id]
Syntax Description
Defaults
IPv4 and unicast address prefixes
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf border-routersOSPF 1 Internal Routing TableCodes: i - Intra-area route, I - Inter-area routei 172.31.97.53 [1] via 172.16.1.53, POS 3/0/0/0, ABR/ASBR , Area 0, SPF 3Table 3 describes the significant fields shown in the display.
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
Defaults
IPv4 and unicast address prefixes
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf databaseOSPF Router with ID (172.20.1.11) (Process ID 1)Router Link States (Area 0)Link ID ADV Router Age Seq# Checksum Link count172.20.1.8 172.20.1.8 1381 0x8000010D 0xEF60 2172.20.1.11 172.20.1.11 1460 0x800002FE 0xEB3D 4172.20.1.12 172.20.1.12 2027 0x80000090 0x875D 3172.20.1.27 172.20.1.27 1323 0x800001D6 0x12CC 3Net Link States (Area 0)Link ID ADV Router Age Seq# Checksum172.22.1.27 172.20.1.27 1323 0x8000005B 0xA8EE172.22.1.11 172.20.1.11 1461 0x8000005B 0x7ACType-10 Opaque Link Area Link States (Area 0)Link ID ADV Router Age Seq# Checksum Opaque ID10.0.0.0 172.20.1.11 1461 0x800002C8 0x8483 010.0.0.0 172.20.1.12 2027 0x80000080 0xF858 010.0.0.0 172.20.1.27 1323 0x800001BC 0x919B 010.0.0.1 172.20.1.11 1461 0x8000005E 0x5B43 1Table 4 describes the significant fields shown in the display.
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-summaryOSPF Router with ID (192.168.0.1) (Process ID 300)Summary ASB Link States (Area 0.0.0.0)LS age: 1463Options: (No TOS-capability)LS Type: Summary Links (AS Boundary Router)Link State ID: 172.17.245.1 (AS Boundary Router address)Advertising Router: 172.17.241.5LS Seq Number: 80000072Checksum: 0x3548Length: 28Network Mask: /0TOS: 0 Metric: 1Table 5 describes the significant fields shown in the display.
The following is sample output from the show ospf database command with the external keyword:
RP/0/RP0/CPU0:router# show ospf database externalOSPF Router with ID (192.168.0.1) (Process ID 300)Type-5 AS External Link StatesLS age: 280Options: (No TOS-capability)LS Type: AS External LinkLink State ID: 172.17.0.0 (External Network Number)Advertising Router: 172.17.70.6LS Seq Number: 80000AFDChecksum: 0xC3ALength: 36Network Mask: 255.255.0.0Metric Type: 2 (Larger than any link state path)TOS: 0Metric: 1Forward Address: 0.0.0.0External Route Tag: 0Table 6 describes the significant fields shown in the display.
The following is sample output from the show ospf database command with the network keyword:
RP/0/RP0/CPU0:router# show ospf database networkOSPF Router with ID (192.168.0.1) (Process ID 300)Net Link States (Area 0.0.0.0)LS age: 1367Options: (No TOS-capability)LS Type: Network LinksLink State ID: 172.23.1.3 (address of Designated Router)Advertising Router: 192.168.0.1LS Seq Number: 800000E7Checksum: 0x1229Length: 52Network Mask: /24Attached Router: 192.168.0.1Attached Router: 172.23.241.5Attached Router: 172.23.1.1Attached Router: 172.23.54.5Attached Router: 172.23.1.5Table 7 describes the significant fields shown in the display.
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/RP0/CPU0:router# show ospf database opaque-area adv-router 172.20.1.12OSPF Router with ID (172.20.1.11) (Process ID 1)Type-10 Opaque Link Area Link States (Area 0)LS age: 224Options: (No TOS-capability, DC)LS Type: Opaque Area LinkLink State ID: 1.0.0.0Opaque Type: 1Opaque ID: 0Advertising Router: 172.20.1.12LS Seq Number: 80000081Checksum: 0xF659Length: 132Fragment number : 0MPLS TE router ID : 172.20.1.12Link connected to Point-to-Point networkLink ID : 172.20.1.11Interface Address : 172.21.1.12Neighbor Address : 172.21.1.11Admin Metric : 10Maximum bandwidth : 193000Maximum reservable bandwidth : 125000Number of Priority : 8Priority 0 : 125000 Priority 1 : 125000Priority 2 : 125000 Priority 3 : 125000Priority 4 : 125000 Priority 5 : 125000Priority 6 : 125000 Priority 7 : 100000Affinity Bit : 0x0Number of Links : 1The following is sample output from the show ospf database command that displays a Type 10, Router Information LSA:
RP/0/RP0/CPU0:router# show ospf database opaque-area 4.0.0.0OSPF Router with ID (3.3.3.3) (Process ID orange)Type-10 Opaque Link Area Link States (Area 0)LS age: 105Options: (No TOS-capability, DC)LS Type: Opaque Area LinkLink State ID: 4.0.0.0Opaque Type: 4Opaque ID: 0Advertising Router: 3.3.3.3LS Seq Number: 80000052Checksum: 0x34e2Length: 52Fragment number: 0Router Information TLV: Length: 4Capabilities:Graceful Restart Helper CapableTraffic Engineering enabled areaAll capability bits: 0x50000000PCE Discovery TLV: Length: 20IPv4 Address: 3.3.3.3PCE Scope: 0x20000000Compute Capabilities:Inter-area default (Rd-bit)Compute Preferences:Intra-area: 0 Inter-area: 0Inter-AS: 0 Inter-layer: 0Table 8 describes the significant fields shown in the display.
The following is sample output from the show ospf database command with the router keyword:
RP/0/RP0/CPU0:router# show ospf database routerOSPF Router with ID (192.168.0.1) (Process ID 300)Router Link States (Area 0.0.0.0)LS age: 1176Options: (No TOS-capability)LS Type: Router LinksLink State ID: 172.23.21.6Advertising Router: 172.23.21.6LS Seq Number: 80002CF6Checksum: 0x73B7Length: 120AS Boundary RouterNumber of Links: 8Link connected to: another Router (point-to-point)(Link ID) Neighboring Router ID: 172.23.21.5(Link Data) Router Interface address: 172.23.21.6Number of TOS metrics: 0TOS 0 Metrics: 2Table 9 describes the significant fields shown in the display.
The following is sample output from show ospf database command with the summary keyword:
RP/0/RP0/CPU0:router# show ospf database summaryOSPF Router with ID (192.168.0.1) (Process ID 300)Summary Net Link States (Area 0.0.0.0)LS age: 1401Options: (No TOS-capability)LS Type: Summary Links (Network)Link State ID: 172.23.240.0 (Summary Network Number)Advertising Router: 172.23.241.5LS Seq Number: 80000072Checksum: 0x84FFLength: 28Network Mask: /24TOS: 0 Metric: 1Table 10 describes the significant fields shown in the display.
The following is sample output from show ospf database command with the database-summary keyword:
RP/0/RP0/CPU0:router# show ospf database database-summaryOSPF Router with ID (172.19.65.21) (Process ID 1)Area 0 database summaryLSA Type Count Delete MaxageRouter 2 0 0Network 1 0 0Summary Net 2 0 0Summary ASBR 0 0 0Type-7 Ext 0 0 0Opaque Link 0 0 0Opaque Area 0 0 0Subtotal 5 0 0Process 1 database summaryLSA Type Count Delete MaxageRouter 2 0 0Network 1 0 0Summary Net 2 0 0Summary ASBR 0 0 0Type-7 Ext 0 0 0Opaque Link 0 0 0Opaque Area 0 0 0Type-5 Ext 2 0 0Opaque AS 0 0 0Total 7 0 0Table 11 describes the significant fields shown in the display.
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.
show ospf [process-name] [vrf {vrf-name | all}] [area-id] flood-list [interface-type interface-instance]
Syntax Description
Defaults
All interfaces.
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 POS 3/0/0/0:
RP/0/RP0/CPU0:router# show ospf flood-list POS 3/0/0/0Interface POS3/0/0/0, Queue length 20Link state retransmission due in 12 msecDisplaying 6 entries from flood list:Type LS ID ADV RTR Seq NO Age Checksum5 10.2.195.0 200.0.0.163 0x80000009 0 0xFB615 10.1.192.0 200.0.0.163 0x80000009 0 0x29385 10.2.194.0 200.0.0.163 0x80000009 0 0x7575 10.1.193.0 200.0.0.163 0x80000009 0 0x1E425 10.2.193.0 200.0.0.163 0x80000009 0 0x124D5 10.1.194.0 200.0.0.163 0x80000009 0 0x134CTable 12 describes the significant fields shown in the display.
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 instance]
Syntax Description
Defaults
All interfaces
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following is sample output from the show ospf interface command:
RP/0/RP0/CPU0:router# show ospf interfacePOS0/2/0/1 is up, line protocol is upInternet Address 121.10.10.2/24, Area 2Process ID 1, Router ID 200.2.2.2, Network Type POINT_TO_POINT, Cost: 1Transmit Delay is 1 sec, State POINT_TO_POINT,Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 00:00:04Index 1/3, flood queue length 0Next 0(0)/0(0)Last flood scan length is 3, maximum is 10Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 1, Adjacent neighbor count is 1Adjacent with neighbor 101.3.3.3Suppress hello for 0 neighbor(s)Multi-area interface Count is 1Multi-Area interface exist in area 1 Neighbor Count is 1POS0/3/0/0 is up, line protocol is upInternet Address 145.10.10.2/16, Area 3Process ID 1, Router ID 200.2.2.2, Network Type POINT_TO_POINT, Cost: 1Transmit Delay is 1 sec, State POINT_TO_POINT,BFD enabled, BFD interval 15 msec, BFD multiplier 3Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Index 1/5, flood queue length 0Next 0(0)/0(0)Last flood scan length is 3, maximum is 11Last flood scan time is 0 msec, maximum is 1 msecNeighbor Count is 1, Adjacent neighbor count is 1Adjacent with neighbor 101.3.3.3Suppress hello for 0 neighbor(s)Message digest authentication enabledYoungest key id is 1Multi-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/RP0/CPU0:P11_CRS-4 show ospf interface pos 0/2/1/0POS0/2/1/0 is up, line protocol is upInternet Address 10.111.4.11/24, Area 0Process ID 100, Router ID 10.11.11.11, Network Type POINT_TO_POINT, Cost: 1LDP Sync Enabled, Sync Status: AchievedTransmit Delay is 1 sec, State POINT_TO_POINT,Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Non-Stop Forwarding (NSF) enabledHello due in 00:00:09Index 5/5, flood queue length 0Next 0(0)/0(0)Last flood scan length is 4, maximum is 7Last flood scan time is 0 msec, maximum is 1 msecNeighbor Count is 1, Adjacent neighbor count is 1Adjacent with neighbor 10.1.1.1Suppress hello for 0 neighbor(s)Multi-area interface Count is 0Table 13 describes the significant fields shown in the display.
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] [interface-type interface-instance] mpls traffic-eng {link | fragment}
Syntax Description
Defaults
All links or fragments
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following is sample output from the show ospf mpls traffic-eng command when the link keyword is specified:
RP/0/RP0/CPU0:router# show ospf mpls traffic-eng linkOSPF 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 67441Link connected to Point-to-Point networkLink ID : 10.10.10.8Interface Address : 10.10.10.2Neighbor Address : 10.10.10.3Admin Metric : 0Maximum bandwidth : 19440000Maximum global pool reservable bandwidth : 25000000Maximum sub pool reservable bandwidth : 3125000Number of Priority : 8Global pool unreserved BWPriority 0 : 25000000 Priority 1 : 25000000Priority 2 : 25000000 Priority 3 : 25000000Priority 4 : 25000000 Priority 5 : 25000000Priority 6 : 25000000 Priority 7 : 25000000Sub pool unreserved BWPriority 0 : 3125000 Priority 1 : 3125000Priority 2 : 3125000 Priority 3 : 3125000Priority 4 : 3125000 Priority 5 : 3125000Priority 6 : 3125000 Priority 7 : 3125000Affinity Bit : 0Links in hash bucket 8.Link is associated with fragment 0. Link instance is 67441Link connected to Point-to-Point networkLink ID : 10.1.1.1Interface Address : 10.10.25.4Neighbor Address : 10.10.25.5Admin Metric : 0Maximum bandwidth : 19440000Maximum global pool reservable bandwidth : 25000000Maximum sub pool reservable bandwidth : 3125000Number of Priority : 8Global pool unreserved BWPriority 0 : 25000000 Priority 1 : 25000000Priority 2 : 25000000 Priority 3 : 25000000Priority 4 : 25000000 Priority 5 : 25000000Priority 6 : 25000000 Priority 7 : 25000000Sub pool unreserved BWPriority 0 : 3125000 Priority 1 : 3125000Priority 2 : 3125000 Priority 3 : 3125000Priority 4 : 3125000 Priority 5 : 3125000Priority 6 : 3125000 Priority 7 : 3125000Affinity Bit : 0Table 14 describes the significant fields shown in the display.
The following is sample output from the show ospf mpls traffic-eng command when the fragment keyword is specified:
RP/0/RP0/CPU0:router# show ospf mpls traffic-eng fragmentOSPF 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 10.10.10.10Next fragment ID is 2Fragment 0 has 1 link. Fragment instance is 67441.Fragment has 1 link the same as last update.Fragment advertise MPLS router addressLink is associated with fragment 0. Link instance is 67441Link connected to Point-to-Point networkLink ID : 10.1.1.1Interface Address : 10.10.25.4Neighbor Address : 10.10.25.5Admin Metric : 0Maximum bandwidth : 19440000Maximum global pool reservable bandwidth : 25000000Maximum sub pool reservable bandwidth : 3125000Number of Priority : 8Global pool unreserved BWPriority 0 : 25000000 Priority 1 : 25000000Priority 2 : 25000000 Priority 3 : 25000000Priority 4 : 25000000 Priority 5 : 25000000Priority 6 : 25000000 Priority 7 : 25000000Sub pool unreserved BWPriority 0 : 3125000 Priority 1 : 3125000Priority 2 : 3125000 Priority 3 : 3125000Priority 4 : 3125000 Priority 5 : 3125000Priority 6 : 3125000 Priority 7 : 3125000Affinity Bit : 0Fragment 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 67441Link connected to Point-to-Point networkLink ID : 10.10.10.8Interface Address : 10.10.10.2Neighbor Address : 10.10.10.3Admin Metric : 0Maximum bandwidth : 19440000Maximum global pool reservable bandwidth : 25000000Maximum sub pool reservable bandwidth : 3125000Number of Priority : 8Global pool unreserved BWPriority 0 : 25000000 Priority 1 : 25000000Priority 2 : 25000000 Priority 3 : 25000000Priority 4 : 25000000 Priority 5 : 25000000Priority 6 : 25000000 Priority 7 : 25000000Sub pool unreserved BWPriority 0 : 3125000 Priority 1 : 3125000Priority 2 : 3125000 Priority 3 : 3125000Priority 4 : 3125000 Priority 5 : 3125000Priority 6 : 3125000 Priority 7 : 3125000Affinity Bit : 0Table 15 describes the significant fields shown in the display.
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 [[interface-type interface-instance] [neighbor-id] [detail] | area-sorted]
Syntax Description
Defaults
All neighbors
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf neighborNeighbors for OSPFNeighbor ID Pri State Dead Time Address Interface192.168.199.137 1 FULL/DR 0:00:31 172.31.80.37 POS 0/3/0/2Neighbor is up for 18:45:22192.168.48.1 1 FULL/DROTHER 0:00:33 192.168.48.1 POS 0/3/0/3Neighbor is up for 18:45:30192.168.48.200 1 FULL/DROTHER 0:00:33 192.168.48.200 POS 0/3/0/3Neighbor is up for 18:45:25192.168.199.137 5 FULL/DR 0:00:33 192.168.48.189 POS 0/3/0/3Neighbor is up for 18:45:27Table 16 describes the significant fields shown in the display.
The following is sample output showing summary information about the neighbor that matches the neighbor ID:
RP/0/RP0/CPU0:router# show ospf neighbor 192.168.199.137Neighbor 192.168.199.137, interface address 172.31.80.37In the area 0.0.0.0 via interface POS 0/3/0/2Neighbor priority is 1, State is FULL, 6 state changesDR is 0.0.0.0 BDR is 0.0.0.0Options is 0x2Dead timer due in 0:00:32 Neighbor is up for 18:45:30 Number of DBD retrans during last exhange 0Index 1/1, retransmission queue length 0, number of retransmission 0First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)Last retransmission scan length is 0, maximum is 0Last retransmission scan time is 0 msec, maximum 0 msecNeighbor 192.168.199.137, interface address 192.168.48.189In the area 0.0.0.0 via interface POS 0/3/0/3Neighbor priority is 5, State is FULL, 6 state changesOptions is 0x2Dead timer due in 0:00:32Neighbor is up for 18:45:30 Number of DBD retrans during last exhange 0Index 1/1, retransmission queue length 0, number of retransmission 0First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)Last retransmission scan length is 0, maximum is 0Last retransmission scan time is 0 msec, maximum 0 msecTotal neighbor count: 2Table 17 describes the significant fields shown in the display.
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/RP0/CPU0:router# show ospf neighbor POS 0/3/0/2 192.168.199.137Neighbor 192.168.199.137, interface address 172.31.80.37In the area 0.0.0.0 via interface POS 0/3/0/2Neighbor priority is 1, State is FULL, 6 state changesDR is 0.0.0.0 BDR is 0.0.0.0Options is 0x2Dead timer due in 0:00:32 Neighbor is up for 18:45:30 Number of DBD retrans during last exhange 0Index 1/1, retransmission queue length 0, number of retransmission 0First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)Last retransmission scan length is 0, maximum is 0Last retransmission scan time is 0 msec, maximum 0 msecTotal neighbor count: 1Table 18 describes the significant fields shown in the display.
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/RP0/CPU0:router# show ospf neighbor POS 0/3/0/3Neighbors for OSPF ospf1ID Pri State Dead Time Address Interface192.168.48.1 1 FULL/DROTHER 0:00:33 192.168.48.1 POS 0/3/0/3Neighbor is up for 18:50:52192.168.48.200 1 FULL/DROTHER 0:00:32 192.168.48.200 POS 0/3/0/3Neighbor is up for 18:50:52192.168.199.137 5 FULL/DR 0:00:32 192.168.48.189 POS 0/3/0/3Neighbor is up for 18:50:52Total neighbor count: 3Table 19 describes the significant fields shown in the display.
The following samples are from output from the show ospf neighbor detail command:
RP/0/RP0/CPU0:router# show ospf neighbor detailNeighbor 192.168.199.137, interface address 172.31.80.37In the area 0.0.0.0 via interface POS 0/3/0/2Neighbor priority is 1, State is FULL, 6 state changesDR is 0.0.0.0 BDR is 0.0.0.0Options is 0x2Dead timer due in 0:00:32 Neighbor is up for 18:45:30 Number of DBD retrans during last exhange 0Index 1/1, retransmission queue length 0, number of retransmission 0First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)Last retransmission scan length is 0, maximum is 0Last retransmission scan time is 0 msec, maximum 0 msecTotal neighbor count: 1Neighbor 10.1.1.1, interface address 192.168.13.1In the area 0 via interface POS0/3/0/1Neighbor priority is 1, State is FULL, 10 state changesDR is 0.0.0.0 BDR is 0.0.0.0Options is 0x52LLS Options is 0x1 (LR)Dead timer due in 00:00:36Neighbor is up for 1w2dNumber of DBD retrans during last exchange 0Index 3/3, retransmission queue length 0, number of retransmission 5First 0(0)/0(0) Next 0(0)/0(0)Last retransmission scan length is 1, maximum is 1Last retransmission scan time is 0 msec, maximum is 0 msecNeighbor 10.4.4.4, interface address 192.168.34.4In the area 0 via interface POS0/3/0/2Neighbor priority is 1, State is FULL, 48 state changesDR is 0.0.0.0 BDR is 0.0.0.0Options is 0x12LLS Options is 0x1 (LR)Dead timer due in 00:00:30Neighbor is up for 00:40:03Number of DBD retrans during last exchange 0Index 2/2, retransmission queue length 0, number of retransmission 6First 0(0)/0(0) Next 0(0)/0(0)Last retransmission scan length is 0, maximum is 1Last retransmission scan time is 0 msec, maximum is 0 msecTable 20 describes the significant fields shown in the display.
Related Commands
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 [interface-type interface-instance] [neighbor-id]
Syntax Description
Defaults
All neighbors
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 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.
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/RP0/CPU0:router# show ospf request-list 10.0.124.4 POS3/0/0/0Request Lists for OSPF pagentNeighbor 10.0.124.4, interface POS3/0/0/0 address 10.3.1.2Type LS ID ADV RTR Seq NO Age Checksum1 192.168.58.17 192.168.58.17 0x80000012 12 0x0036f32 192.168.58.68 192.168.58.17 0x80000012 12 0x00083fTable 21 describes the significant fields shown in the display.
Related Commands
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 [interface-type interface-instance] [neighbor-id]
Syntax Description
Defaults
All neighbors
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf retransmission-list 10.0.124.4 POS3/0/0/0Neighbor 10.0.124.4, interface POS3/0/0/0 address 10.3.1.2Table 22 describes the significant fields shown in the display.
Related Commands
Configures an OSPF routing process.
Displays the first ten link-state requests pending that the local router is making to the specified neighbor and interface.
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
Defaults
All route types
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf routeTopology Table for ospf 1 with ID 10.3.4.2Codes:O - Intra area, O IA - Inter areaO E1 - External type 1, O E2 - External type 2O N1 - NSSA external type 1, O N2 - NSSA external type 2O E2 10.3.1.0/24, metric 110.3.4.1, from 172.16.10.1, via POS 0/1/0/1O 10.3.4.0/24, metric 156210.3.4.2, directly connected, via POS 0/1/0/1O E2 10.1.0.0/16, metric 110.3.4.1, from 172.16.10.1, via POS 0/1/0/1O IA 10.10.10.0/24, metric 157210.3.4.1, from 172.16.10.1, via POS 0/1/0/1O E2 130.10.10.0/24, metric 2010.3.4.1, from 172.16.10.1, via POS 0/1/0/1Table 23 describes the significant fields shown in the display.
The following is sample output from the show ospf route command with a process name of 100:
RP/0/RP0/CPU0:router# show ospf 100 routeTopology Table for ospf 100 with ID 172.23.54.14Codes:O - Intra area, O IA - Inter areaO E1 - External type 1, O E2 - External type 2O N1 - NSSA external type 1, O N2 - NSSA external type 2O 10.1.5.0/24, metric 156210.1.5.14, directly connected, via POS 0/3/0/3O IA 21.0.0.0/24, metric 157210.1.5.12, from 172.23.54.12, via POS 0/3/0/3O 10.0.0.0/24, metric 1010.0.0.12, directly connected, via POS 0/2/0/3Table 24 describes the significant fields shown in the display.
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/RP0/CPU0:router# show ospf route 10.0.0.0/24Topology Table for ospf 100 with ID 172.23.54.14Codes:O - Intra area, O IA - Inter areaO E1 - External type 1, O E2 - External type 2O N1 - NSSA external type 1, O N2 - NSSA external type 2O IA 10.0.0.0/24, metric 157210.1.5.12, from 172.23.54.12, via POS 0/3/0/3Table 25 describes the significant fields shown in the display.
Related Commands
show ospf sham-links
To display Open Shortest Path First (OSPF) sham-link information, use the show ospf sham-links command in EXEC mode.
show ospf [process-name] [vrf {vrf-name | all}] sham-links
Syntax Description
Defaults
No default behavior or values
Command Modes
EXEC
Command History
Release 3.6.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf 1 vrf vrf_1 sham-linksSham Links for OSPF 1, VRF vrf_1Sham Link OSPF_SL0 to address 10.0.0.3 is upArea 0, source address 10.0.0.1IfIndex = 185Run as demand circuitDoNotAge LSA allowed., Cost of using 1Transmit Delay is 1 sec, State POINT_TO_POINT,Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 00:00:04Adjacency State FULL (Hello suppressed)Number of DBD retrans during last exchange 0Index 2/2, retransmission queue length 0, number of retransmission 0First 0(0)/0(0) Next 0(0)/0(0)Last retransmission scan length is 0, maximum is 0Last retransmission scan time is 0 msec, maximum is 0 msecKeychain-based authentication enabledKey id used is 2Table 26 describes the significant fields shown in the display.
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.
show ospf [process-name] [vrf {vrf-name | all}] summary-prefix
Syntax Description
Defaults
All summary prefixes
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf summary-prefixOSPF Process 1, summary-prefix10.1.0.0/255.255.0.0 Metric 20, Type 2, Tag 0Table 27 describes the significant fields shown in the display.
Related Commands
Configures an OSPF routing process.
Creates aggregate addresses for routes being redistributed from another routing protocol into the OSPF protocol.
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.
show ospf [process-name] [vrf {vrf-name | all}] virtual-links
Syntax Description
Defaults
All virtual links
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# show ospf virtual-linksVirtual Link to router 172.31.101.2 is upTransit area 0.0.0.1, via interface POS 0/3/0/0, Cost of using 10Transmit Delay is 1 sec, State POINT_TO_POINTTimer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 0:00:08Adjacency State FULLTable 28 describes the significant fields shown in the display.
Related Commands
show protocols (OSPF)
To display information about the OSPFv2 processes running on the router, use the show protocols command in EXEC mode.
show protocols [afi-all | ipv4 | ipv6] [all | protocol]
Syntax Description
Defaults
No default behavior or value
Command Modes
EXEC
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following is an OSPF configuration and the resulting show protocols ospf display:
RP/0/RP0/CPU0:router# show running router ospf 1router ospf 1router-id Loopback0nsfredistribute connectedredistribute isis 3area 0mpls traffic-enginterface Loopback0!interface Loopback1!interface Loopback2!interface POS 0/3/0/0!interface POS 0/3/0/1!interface POS 0/3/0/2!interface POS 0/3/0/3!!mpls traffic-eng router-id Loopback0!RP/0/RP0/CPU0:router# show protocols ospfRouting Protocol OSPF 1Router Id: 55.55.55.55Distance: 110Non-Stop Forwarding: EnabledRedistribution:connectedisis 3Area 0MPLS/TE enabledPOS 0/3/0/3POS 0/3/0/2POS 0/3/0/1POS 0/3/0/0Loopback2Loopback0Table 29 describes the significant fields shown in the display.
stub (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.
stub [no-summary]
no stub
Syntax Description
no-summary
(Optional) Prevents an Area Border Router (ABR) from sending summary link advertisements into the stub area.
Defaults
No stub area is defined.
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# area 10.0.0.0RP/0/RP0/CPU0:router(config-ospf-ar)# stubRP/0/RP0/CPU0:router(config-ospf-ar)# default-cost 20RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/3/0/3Related Commands
Enables authentication for an OSPF area.
Specifies a cost for the default summary route sent into a stub area.
summary-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.
summary-prefix address mask [not-advertise | tag tag]
no summary-prefix address mask
Syntax Description
Defaults
When this command is not used, specific addresses are created for each route from another route source being distributed into the OSPF protocol.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# summary-prefix 10.1.0.0 255.255.0.0Related Commands
timers 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.
timers lsa group-pacing seconds
no timers lsa group-pacing
Syntax Description
seconds
Interval (in seconds) at which LSAs are grouped and refreshed, checksummed, or aged. Range is 10 seconds to 1800 seconds.
Defaults
seconds: 240 seconds
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
.Examples
The following example shows how to change the OSPF pacing between LSA groups to 60 seconds:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# timers lsa group-pacing 60timers 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 seconds
no timers lsa min-arrival
Syntax Description
seconds
Minimum interval (in seconds) between instances of the same LSA. Range is 0 to 1800 seconds.
Defaults
seconds: 1 second
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to change the minimum interval between accepting the same LSA to 2 seconds:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# timers lsa min-arrival 2timers 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
timers throttle lsa all start-interval hold-interval max-interval
no timers throttle lsa all
Syntax Description
Defaults
start-interval: 500 milliseconds
hold-interval: 5000 milliseconds
max-interval: 5000 millisecondsCommand Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# timers throttle lsa all 5 1000 90000The following example is output from the show ospf command that displays the modified LSA throttle settings:
RP/0/RP0/CPU0:router# show ospfRouting Process "ospf 1" with ID 1.1.1.1Supports only single TOS(TOS0) routesSupports opaque LSAIt is an area border routerInitial SPF schedule delay 5000 msecsMinimum hold time between two consecutive SPFs 10000 msecsMaximum wait time between two consecutive SPFs 10000 msecsInitial LSA throttle delay 500 msecsMinimum hold time for LSA throttle 1000 msecsMaximum wait time for LSA throttle 90000 msecsMinimum LSA interval 1000 msecs. Minimum LSA arrival 1 secsMaximum number of configured interfaces 255Number of external LSA 0. Checksum Sum 00000000Number of opaque AS LSA 0. Checksum Sum 00000000Number of DCbitless external and opaque AS LSA 0Number of DoNotAge external and opaque AS LSA 0Number of areas in this router is 2. 2 normal 0 stub 0 nssaExternal flood list length 0Non-Stop Forwarding enabledArea BACKBONE(0) (Inactive)Number of interfaces in this area is 2SPF algorithm executed 8 timesNumber of LSA 2. Checksum Sum 0x01ba83Number of opaque link LSA 0. Checksum Sum 00000000Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 0Area 1Number of interfaces in this area is 1SPF algorithm executed 9 timesNumber of LSA 2. Checksum Sum 0x0153eaNumber of opaque link LSA 0. Checksum Sum 00000000Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 0Related Commands
timers 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
timers throttle spf spf-start spf-hold spf-max-wait
no timers throttle spf
Syntax Description
Defaults
SPF throttling is not set.
Command Modes
Router configuration
VRF configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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
Task ID
Examples
The following example shows how to change the start, hold, and maximum wait interval values to 5, 1000, and 90000 milliseconds, respectively:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# timers throttle spf 5 1000 90000transmit-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.
transmit-delay seconds
no transmit-delay seconds
Syntax Description
Defaults
seconds: 1 second
Command Modes
Router configuration
Area configuration
Interface configuration
Virtual-link configuration
VRF configuration
Multi-area configuration
Sham-link configurationCommand 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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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, this means that 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 Packet-over-SONET/SDH (POS) interface POS 0/3/0/0:
RP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# area 0RP/0/RP0/CPU0:router(config-ospf-ar)# interface POS 0/3/0/0RP/0/RP0/CPU0:router(config-ospf-ar-if)# transmit-delay 3Related Commands
virtual-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.
virtual-link router-id
no virtual-link router-id
Syntax Description
Defaults
No virtual links are defined.
Command Modes
Area configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# area 10.0.0.0RP/0/RP0/CPU0:router(config-ospf-ar)# virtual-link 10.3.4.5RP/0/RP0/CPU0:router(config-ospf-ar-vl)#The following example shows how to establish a virtual link with clear text authentication called mykey:
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 201RP/0/RP0/CPU0:router(config-ospf)# area 10.0.0.0RP/0/RP0/CPU0:router(config-ospf-ar)# virtual-link 10.3.4.5RP/0/RP0/CPU0:router(config-ospf-ar-vl)# authentication-key 0 mykeyRelated Commands
Enables authentication for an OSPF area.
Displays parameters and the current state of OSPF virtual links
vrf (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.
vrf vrf-name
no vrf vrf-name
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.
Defaults
No OSPF VRF is defined.
Command Modes
Router configuration
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. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
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 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 Packet-over-SONET/SDH (POS) interface 0/2/0/0. POS interface 0/2/0/0 is bound to VRF vrf1 automatically.
RP/0/RP0/CPU0:router# configureRP/0/RP0/CPU0:router(config)# router ospf 1RP/0/RP0/CPU0:router(config-ospf)# vrf vrf1RP/0/RP0/CPU0:router(config-ospf-vrf)# interface POS 0/2/0/0Related Commands
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