OSPF Retransmissions Limit

The OSPF Retransmissions Limit feature adds a limit to the number of retransmissions of database exchange and update packets for both demand and non-demand circuits. The retransmission of these packets stops once this retry limit is reached, thus preventing unnecessary use of the link in continual retransmission of the packets if, for some reason, a neighbor is not responding during adjacency forming. This feature module describes the change in how the Open Shortest Path First (OSPF) protocol handles retransmissions.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tooland the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Restrictions For OSPF Retransmissions Limit

The limit to the number of retransmissions does not apply for update packets on nonbroadcast multiaccess (NBMA) point-to-multipoint direct circuits. In this situation, the dead timer is used to end communication with non-responding neighbors and thus stop the retransmissions.

Information About OSPF Retransmissions Limit

Overview About OSPF Retransmissions Limit

Cisco IOS Release 12.2(4)T added a limit to the number of retransmissions of database exchange and update packets for both demand and non-demand circuits. The retransmission of these packets stops once this retry limit is reached, thus preventing unnecessary use of the link in continual retransmission of the packets if, for some reason, a neighbor is not responding during adjacency forming.

The limit for both demand circuit and non-demand circuit retransmissions is 24.

The limit-retransmissions command allows you to either remove (disable) the limit or change the maximum number of retransmissions to be a number from 1 to 255.

Benefits

The limit-retransmissions command provides for backward compatibility for previous or other releases of Cisco IOS or other routers that do not have this feature.

How to Configure OSPF Retransmissions Limit

Setting OSPF Retransmission Limits

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router ospf process-ID
  4. limit retransmissions {[dc {max-number | disable }] [non-dc {max-number | disable }]}
  5. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

router ospf process-ID

Example:

Device(config)# router ospf 18

Configures OSPF routing process and enters OSPF router configuration mode.

Step 4

limit retransmissions {[dc {max-number | disable }] [non-dc {max-number | disable }]}

Example:

Device(config-router)# limit retransmissions dc 5

Sets the limit in the number of retransmissions of database exchange and update packets for both demand and non-demand circuits.

Step 5

end

Example:

Device(config-router)# end

Exits address router configuration mode and returns to privileged EXEC mode.

Additional References for OSPF Retransmissions Limit

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

Configuring OSPF

IP Routing: OSPF Configuration Guide

OSPF Commands

IP Routing: OSPF Command Reference

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Feature Information for OSPF Retransmissions Limit

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1. Feature Information for OSPF Retransmissions Limit

Feature Name

Releases

Feature Information

OSPF Retransmissions Limit

12.2(11)T

15.2(1)SY

The OSPF Retransmissions Limit feature adds a limit to the number of retransmissions of database exchange and update packets for both demand and non-demand circuits. The retransmission of these packets stops once this retry limit is reached, thus preventing unnecessary use of the link in continual retransmission of the packets if, for some reason, a neighbor is not responding during adjacency forming. .

The following commands were introduced or modified: limit retransmissions .