3Com Switch 7750 Configuration Guide Guide

Displaying Super VLAN 117
■ After establishing the mapping between the sub VLAN and the super VLAN,
you can still add (or delete) ports to (from) the sub VLAN.
■ A super VLAN can establish mappings with 128 sub VLANs.
■ The system can create up to 1024 sub VLANs.
Configuring Super VLAN
to Support DHCP Relay
With DHCP relay function enabled on the VLAN interface of the super VLAN, the
hosts of all sub VLANs that map with the super VLAN can dynamically obtain IP
addresses from the outside networks.
With the DHCP relay function enabled on the VLAN interface of the super VLAN,
the host of the sub VLAN that maps the interface and the DHCP host in another
network segment can forward the DHCP packets to each other, so as to assist the
hosts in the sub VLANs to finish the dynamic configuration of IP address.
Configuration Prerequisites
■ Configure a super VLAN and a sub VLAN, and establish the mapping between
them.
■ Configure the IP address of the super VLAN to make the hosts in the sub VLAN
being able to communicate with the outside network.
Configuration Procedure
n
■ A super VLAN interface can only correspond to one DHCP server group.
■ The last configuration will take effect if you execute the dhcp-server groupNo
command.
■ The group number specified in the dhcp-server groupNo command needs to
be configured first in the dhcp-server ip command. Refer to the DHCP part of
the operation manual.
Displaying Super
VLAN
After the above configurations, you can use the display command in any view the
super VLAN configuration and verify the configuration effect.
Operation Command Description
Enter system view system-view -
Enter VLAN interface view of
the super VLAN
interface Vlan-interface
vlan-id
-
Configure the mapping
between the interface and the
DHCP server group
dhcp-server groupNo
Required
By default, the VLAN interface
does not establish homing
relationship with any DHCP
server group.