Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide Chapter 1 IP Address Configuration Commands
3Com Corporation
1-3
Example
# Display how to set IP address of interface Serial 0/0/0 to be allocated by peer through
negotiation.
[3Com-Serial0/0/0] ip address ppp-negotiate
1.1.3 ip address unnumbered
Syntax
ip address unnumbered interface interface-type interface-number
undo ip address unnumbered
View
Interface view
Parameter
interface-type: Name of the unnumbered interface.
interface-number: Serial number of the unnumbered interface.
Description
Use the ip address unnumbered command to enable an interface to borrow the IP
address of another interface.
Use the undo ip address unnumbered command to disable this function on the
interface.
By default, the interface does not borrow IP addresses from other interfaces.
This command is used to enable serial interfaces encapsulated with PPP, HDLC,
Frame Relay, SLIP or Tunnel to borrow IP addresses from Ethernet interface or other
interfaces. Ethernet interfaces however cannot use unnumbered IP addresses.
The interface that uses an unnumbered address has no IP address itself. Its route
cannot be added into the routing table as a result. For connectivity purpose, you must
configure two static routes for it. For more information, refer to the “Routing Protocol”
part of this manual.
Example
# Display how to make the serial interface 0/0/0 encapsulated with PPP borrow the
unnumbered IP address from Ethernet interface 0/0/0.
[3Com-Serial0/0/0] ip address unnumbered Ethernet 0/0/0