Configuring OSPF Configuring OSPF
page 1-26 OmniSwitch 6600 Family Advanced Routing Configuration Guide March 2005
Creating Redistribution Policies and Filters
Redistribution in OSPF controls the way routes are learned and distributed in the OSPF network. Non
OSPF routers can be advertised into the OSPF network as AS-external or NSSA-external routes. NSSA-
external routes are advertised only in OSPF-NSSA areas. Redistribution policies are set on Autonomous
System Boundary Routers (ASBRs) and control how routes from outside the Autonomous System (AS)
are learned and distributed. Redistribution Filters are set on any OSPF router and control how routes on
the router are distributed to other routers in the OSPF network.
To set up redistribution on a router:
1Specify the router as an ASBR, as described in “Specifying an Autonomous System Boundary Router”
on page 1-26. (For redistribution policies only.)
2Enable redistribution, as described in “Enabling Redistribution” on page1-26.
3Create a redistribution policy or filter, as described in “Creating A Redistribution Policy” on page1-27
and “Creating a Redistribution Filter” on page1-27.

Specifying an Autonomous System Boundary Router

Redistribution policies can only be created on ASBRs. ASBRs are routers that are directly connected to a
network outside of the AS (e.g., the internet). To configure a router to be an ASBR, enter the ip ospf asbr
command at the CLI prompt, as shown:
-> ip ospf asbr
You can check to see if a router is an ASBR router by using the show ip ospf command.

Enabling Redistribution

Before using any type of redistribution policy or filter, you must enable redistribution on the router, using
the ip ospf redist status command. To enable redistribution, enter the command at the CLI prompt as
shown:
-> ip ospf redist status enable
To disable redistribution, enter the command as shown:
-> ip ospf redist status disable