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output of "sho ip route"

When you use the sho ip route command, it seems that an IOS router will only show you the best route available for a subnet. For example, I recently did a sho route command and the output only showed a static route to a certain network. I thought that strange because I knew for a fact that that network was being advetised via RIP. Sure enough I found a static route in the router's config. When I deleted the static the RIP route showed. I realize that in my case a static route is preffered over a RIP learned route but sometimes for troubleshooting purposes I would like to see all the routes that the router has. Is this possible? What would the command look like?

Thanks,

Diego

2 REPLIES
Bronze

Re: output of "sho ip route"

The router decides whether or not to install the routes presented by the

routing processes based on the administrative distance of the route in

question. If this path has the lowest administrative distance to this destination

(when compared to the other routes in the table), it's installed in the routing

table. If this route isn't the route with the best administrative distance, then the

route is rejected.

The information above is taken from the following CCO link:

http://www.cisco.com/en/US/tech/tk648/tk365/technologies_tech_note09186a0080094823.shtml

The link above should help in explaining how the routing table is built.

Goodluck.

Re: output of "sho ip route"

In your case, the same route was being advertised via RIP, as well as there was a static route for the same network. A router, uses a factor called Administrative distance. Its nothing but believability of a routing protocol. Static routes have admin distance of 1, while RIP has admin distance of 120. Routes with lower admin distance are preferred over a route with higher admin distance. Thats the reason why, initially the static route was being preferred over the RIP route, and when you removed the static, the RIP route showed up.

Again, to view all the routes, received by the router, it depends on type of routing protocol used. For OSPF, it maintains a database, and can be viewed using command, "show ip ospf database". For EIGRP, all the routes received via EIGRP can be viewed using, "show ip eigrp topology". For BGP, you can use, "show ip bgp" . There is no specific command to see all routes received via rip.

Hope this helps!

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