Configuring redistribution filters


router ospf restrict ip-addr/mask-length

Prevents distribution of the specified range of external routes through an ASBR from sources external to the OSPF domain. This will prevent external routes with the specified IP address/mask from entering the OSPF domain.


This command can be used to help implement inbound traffic filtering.

Default: Allow all supported, external route sources.


Use this command to block unwanted, external routes before enabling route redistribution on the ASBR.


To configure a routing switch operating as an ASBR to filter out redistribution of static, connected, or RIP routes on network, enter the following commands:

switch(config)# router ospf restrict

In the default configuration, redistribution is permitted for all routes from supported sources.