Configuring OSPF to Filter the Routes to Be Advertised

Procedure

1. Run system-view

   The system view is displayed.

2. Run ospf [ process-id ]

   The OSPF process view is displayed.

3. Run filter-policy { acl-number | acl-name acl-name | ip-prefix ip-prefix-name | route-policy route-policy-name } export [ protocol [ process-id ] ]

   OSPF is configured to filter the routes imported using the import-route command. Only the routes that pass the filtering criteria are advertised.

   • The parameter acl-number specifies the number of a basic ACL.
   • The parameter acl-name acl-name specifies the name of an ACL.
   • The parameter ip-prefix ip-prefix-name specifies the name of an IP prefix list.
   • The parameter route-policy route-policy-name specifies the name of a routing policy.

   To filter the routes of a specific routing protocol or process, specify the parameter protocol [ process-id ]. If this parameter is not specified, OSPF filters all the imported routes.

   

   • The import-route command cannot be used to import external default routes.
   • Only for the external routes passing the filtering criteria, OSPF generates Type 5 LSAs to advertise the routes.