Accept policies are applied to incoming traffic to determine whether to add the route to the routing table. Accept policies are applied differently to protocols, as follows:
RIP and BGP—filters apply to all incoming route information.
OSPF—filters apply only to external route information. Internal routing information is not filtered because otherwise, other routers in the OSPF domain can have inconsistent databases that can affect the router view of the network topology.
IS–IS —filters apply to all incoming route information.
In a network with multiple routing protocols, you can prefer specific routes from RIP instead of from OSPF. The network prefix is a commonly used match criterion for accept policies.