How can I set a default route on an IOS Cisco router?

ROUTER>en Password: ROUTER#conf t ROUTER(config)# ip route0.0.0.00.0.0.0 ROUTER(config)#end ROUTER#exit So to recap.
type 'en', then your password, then 'conf t', then ip route0.0.0.00.0.0.0 something, then end and exit to logout :P

What routing protocol are you using?

Wat$Up(config)#ip route0.0.0.00.0.0.0 s0/0/0

s0/0/0 is the exit interface which you need to specify that from which interface router should forward it's data to its neighbouring router  if it doesn't have that specific network in its Routing table. 

OR

Wat$Up(config)#ip route0.0.0.00.0.0.0192.168.0.100

192.168.0.100 is the Next hop IP of your neighbouring router which you need to specify that  which neighbouring router should your router(Wat$Up) forward it's data if it doesn't have that specific network in its Routing table. 

 

P.S

Obvioulsy192.168.0.100 is an example, so you need to know the IP address of your neighbouring router (i.e next hop ip ) which is directly connected to you. 

 

Hope that answers your question.