3Com 7750 Series Command Reference Manual page 96

3Com Switch 7750 Series
Command Reference Guide — IP / IPX
sub: Secondary IP address of a VLAN or loopback interface.
Description
Use the ip address command to specify an IP address and mask for a VLAN or
loopback interface.
Use the undo ip address command to remove an IP address and mask of a VLAN or
loopback interface.
By default, a VLAN or loopback interface has no IP address.
Generally, it is enough to configure one IP address for an interface. However, you can
configure up to eight IP addresses for an interface so that it can be connected to
several subnets. Among these IP addresses, one is the primary IP address and all the
others are secondary ones. The relationship between the primary address and the
secondary addresses is as follows:
When you configure a primary IP address for an interface which already has a
primary IP address, the new address will replace the old one.
If you execute the undo ip address command without any parameter, the switch
deletes both primary and secondary IP addresses of the interface. The undo ip
address ip-address { mask | mask-length } command is used to delete the
primary IP address. The undo ip address ip-address { mask | mask-length } sub
command is used to delete secondary IP addresses.
Note that a VLAN interface cannot be configured with a secondary IP address if the
interface has been configured to obtain an IP address by BOOTP or DHCP.
Related command: display ip interface.
Example
# Specify the IP address and subnet mask of VLAN interface 1 to 129.12.0.1 and
255.255.255.0 respectively.
<3Com>system-view
System View: return to User View with Ctrl+Z.
[3Com]interface Vlan-interface 1
[3Com-Vlan-interface1] ip address 129.12.0.1 255.255.255.0
Chapter 1 IP Address Configuration Commands
1-4