B. router(config)# ip default-route 10.1.1.0
C. router(config)# ip default-gateway 10.1.1.0
D. router(config)# ip route 0.0.0.0 0.0.0.0 10.1.1.1
Answer: D
Explanation:
The command "IP route 0.0.0.0 0.0.0.0
configure a default route. In this case, a default route with a next hop IP address of
10.1.1.1 was configured.
Incorrect Answers:
A. This will be an invalid route, since the "10.1.1.0" value will specify the network mask, which in this case is invalid.
B, C. These commands are invalid. The command "ip default-network" could be used, bit not "ip default-route" or "ip default-gateway".