ip default-network

greekgeek · ‎08-28-2007

I am confused as to when I need to use ip default-network. Wouldn't "ip route" with "ip classless" work just as well?

Mohamed Sobair · ‎08-28-2007

Hi,

The (IP Default-Network) command is very rarly used, I havent seen yet some one using this currently.

1st: it requires IP routing to be enabled.

2nd: when uses this command within RIP domain it creates a RIP default route without using (redistribute static) command under RIP protocol.

3rd: it does add another static-route for the major Network of the Next-hop address, which in most of the cases makes some problems.

4th: ( ISIS - OSPF ) protocols doesn't recognize this command.

5th: It does require (IP Routing) to be enabled.

Summary:

Its with no doubt using a Static-default route is common & always used, comparing with the command (IP default-network).

Regards,

Mohamed Sobair

Edison Ortiz · ‎08-28-2007

ip default-network is just another option for a gateway of last-resort. I would compare it with an ip route 0.0.0.0 0.0.0.0 gateway.

ip classless is a different animal. That command allows the software to forward packets that are destined for unrecognized subnets of directly connected networks.

If you want to remove more about ip default-network, please check out this link:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cr/hirp_r/rte_pih.htm#wp1122621