Chapter 18
Configuring IP Unnumbered Interface
In the following example, Ethernet VLAN 10 is configured as an IP unnumbered interfaces:
Switch> enable
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface vlan 10
Switch(config-if)# ip unnumbered Lookback 0
Configuring IP Unnumbered Interface Support on a Range of Ethernet VLANs
To configure IP unnumbered interface support on a range of Ethernet VLAN interfaces, perform this
task:
Command or Action
Step 1
Switch# enable
Step 2
Switch# configure terminal
Step 3
Switch(config)# interface range {{fastethernet
| gigabitethernet | vlan vlan} slot/interface
{fastethernet | gigabitethernet | vlan vlan}
slot/interface | macro macro-name}
Step 4
Switch(config-if)# ip unnumbered type number
Step 5
Switch(config-if)# exit
Step 6
Switch(config)# end
Step 7
Switch# show running-config
In the following example, VLANs in the range from 1 to 10 are configured as IP unnumbered interfaces,
sharing IP address of Fast Ethernet 3/1:
Switch> enable
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface range vlan 1 - 10
Switch(config-if)# ip unnumbered fastethernet 3/1
Switch(config-if)# exit
Switch(config)# end
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Configuring IP Unnumbered Interface Support with DHCP Server
Purpose
Enables privileged EXEC mode.
Enter your password if prompted.
Enters global configuration mode.
Executes commands on multiple interfaces at the same time.
A hyphen must be entered with a space on either side to
separate the range information.
Enables IP processing on an interface without assigning an
explicit IP address to the interface.
The type and number arguments specify another interface
on which the switch has an assigned IP address. The
specified interface cannot be another unnumbered interface.
Returns to global configuration mode.
Returns to privileged EXEC mode.
Verifies that IP unnumbered support has been configured
correctly.
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