Verifying Route Redistribution

The most important aspect of verifying and confirming the proper redistribution of your routes is to know your network topology intimately. This is even more critical when you have redundant routes to destination networks. The command show ip protocols lists the routing protocols that are configured for use on your router and exhibits the routing processes that the router is redistributing. The show ip route command shows the IP routing table of the router, including all the known network routes and the precise routing protocols that generated them. The ping command verifies end-to-end connectivity between your network devices; however, ping does not offer information about the specific path that the ICMP echo packets are taking as they move through the internetwork. Therefore, you should use the traceroute command to verify that optimal paths are being used between the core (backbone) network and the edge network(s). The traceroute command can be found in the Cisco IOS documentation simply as "trace." The traceroute command sends ICMP echo packets to a destination hostname or IP address, whereas the screen outputs the name and round-trip time in milliseconds of each gateway encountered throughout the internetwork. The traceroute command can also assist you in diagnosing routing devices that are congested or even offline, as well as verify that the best routing paths are being utilized. You can also run the various debug commands for a short period to view the router activity and traffic on your ASBRs and internal routers. Because the debug process is so processor intensive , it is not a recommended practice except for extreme circumstances.