Network Warriors: Configuring a Gateway of Last Resort Using IP Commands

27 January 2011

Commands ip default-gateway, ip default-network and ip route 0.0.0.0 0.0.0.0 explained:

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094374.shtml

Media Strategist said...: Interesting post thank you. Something of note is unlike the ip default-gateway command, you can use ip default-network when ip routing is enabled on the Cisco router. When you configure ip default-network the router considers routes to that network for installation as the gateway of last resort on the router.

I had two WAN clouds, no over lapping subnets one AS but I wanted to keep the gateways of last resort separate so I thought I would share the solution

using EIGRP I wanted to propagate the route that is the default candidate but I did not want other routers using it as a candidate default for the purpose of determining the gateway of last resort, you can use the following command(s):

router eigrp default-information out|in
where the ACL is an access-list specifying the routes for which the candidate default information is to be propagated.

by using 'no default-information out', none of the outbound routes that are propagated outside of the router will be considered as candidate defaults in the router's neighbors.

Basically, the 'default-information' command sets/unsets the 'exterior flag' for EIGRP routes so that the routes can be sent/received but not considered as default candidates...

By the way, I love the title of your blog :)

Jeff Dahlgren
http://networkwarriors.com; April 9, 2011 at 10:51 PM