routing out of serial and isdn interfaces

[carl_townshend]

Hi all, when routing out of serial, and isdn interfaces, how come we can point the traffic out of the interface rather than a next hop ip address and it still works ?

[smahbub]

You can use exit interface in place of the next-hop ip-address if you want,but its got to be on a point-to-point link,such as a WAN.This command won't work on a LAN such as Ethernet.

The command to configure ip route using next-hop_address or exitinterface is:

ip route [destination_network] [mask] [next-hop_address or exitinterface]

Example:

ip route 172.16.3.0 255.255.255.0 serial 0/0

[carl_townshend]

how come we dont need to use a next hop ip address in this case ?