O'Reilly logo

Routing TCP/IP, Volume I (CCIE Professional Development) by Jeff Doyle

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Configuring Default Routes and ODR

Default routes can be configured either on each router that needs a default route or on one router that in turn advertises the routes to its peers. The case studies of this section examine both methods.

Recall from the discussion in Chapter 5, “Routing Information Protocol (RIP),” of classful route lookups that a router will first match a major network number and then match the subnet. If a subnet cannot be matched, the packet will be dropped. Classful route lookup is the default behavior on Cisco routers; lookups can be changed to classless (even for classful routing protocols) with the global command ip classless.

Note

Routers using a default route should perform classless lookups.

Any router using a default ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required