(<Migration of routing protocol> ·Start the Secondary address, configure the new routing protocol, and delete the original IP address. Note: OSPF and Eigrp cannot use Secondary addresses to establish neighbors. <Redistribution of Routing Protocols> Redistribution refers to the ability of border routers connected to different routing domains to exchange and advertise routing information between different autonomous systems. Redistribution principle: Routes must be in the routing table to be redistributed)