What is IP unnumbered?
In Cisco routers, the ip unnumbered <other_interface> command allows you to
borrow the IP address of another interface.
Although the Cisco help page
[http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094e8d.shtml#unnumbered_iface]
explains in detail how to
