Cisco Cisco IOS Software Release 12.4(15)T

 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a 
specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. 
Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images 
support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to 

. An account on Cisco.com is not required.

 lists only the Cisco IOS software release that introduced support for a given feature in a given 

Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS 
software release train also support that feature.

OSPF Mechanism to Exclude Connected IP 
Prefixes from LSA Advertisements

12.4(15)T

This document describes the Open Shortest Path First 
(OSPF) mechanism to exclude IP prefixes of connected 
networks from link-state advertisements (LSAs). When 
OSPF is deployed in large networks, limiting the number of 
IP prefixes that are carried in the OSPF LSAs can speed up 
OSPF convergence.

This feature can also be utilized to enhance the security of 
an OSPF network by allowing the network administrator to 
prevent IP routing toward internal nodes.