OSPF and BGP requires route policy support. Figure: BGP route policy diagram and Figure: OSPF route policy diagram show where route policies are evaluated in the protocol. Figure: BGP route policy diagram shows BGP which applies a route policy as an internal part of the BGP route selection process. Figure: OSPF route policy diagram shows OSPF which applies routing policies at the edge of the protocol, to control only the routes that are announced to or accepted from the Route Table Manager (RTM).
Figure: BGP route policy diagram
