Isolate -User -Vlan Configuration; Isolate-User-Vlan Overview - 3Com 7757 Configuration Manual

13
Isolate-User-VLAN
Overview
Introduction to
Isolate-User-VLAN
Isolate-User-VLAN
Packets Forwarding
Process
I -U
SOLATE
C
ONFIGURATION
Isolate-user-VLAN is designed for saving VLAN resource by means of copying MAC
address entries among the MAC address tables of VLANs in the network, which is
utilizing the feature that an hybrid port removes the VLAN tag of packets coming
from multiple VLANs.
Isolate-user-VLAN adopts Layer 2 VLAN structure, you need to configure two types
of VLAN, isolate-user-VLAN and secondary VLAN.
An isolate-user-VLAN can match with multiple secondary VLANs. By setting the
hybrid attribute for a port, ports included in all the secondary VLANs and the
uplink port of a switch can all belong to an isolate-user-VLAN. At the same time,
you should configure the uplink port to remove the VLAN tags of all the secondary
VLAN packets forwarded by it.
In this case, for the upper layer switch, all the packets received from the lower
stream are without VLAN tags. Therefore, the switch can reset the local VLAN
structure to save VLAN resource without considering the VLAN configuration in
the lower layer.
Figure 35 is the diagram for isolate-user-VLAN application, the following content
describes the isolate-user-VLAN packets forwarding process based on this figure.
Configure Switch B
Configure port Ethernet2/0/4 as a hybrid port, with the default VLAN ID being
■
3. At the same time, this port belongs to VLAN 3 and VLAN 5, and performs
untag operation (removing of VLAN tag) on the packets from VLAN 3 and
VLAN 5.
Configure port Ethernet2/0/1 as a hybrid port, with the default VLAN ID being
■
5. At the same time, this port belongs to VLAN 3 and VLAN 5, and performs
untag operation (removing of VLAN tag) on the packets from VLAN 3 and
VLAN 5.
Configure Switch A
To ensure that packets sent by Switch A can be forwarded by Switch B according
to the VLAN configurations of the lower layer devices, you need to configure the
port through which Switch A connects to Switch B to remove VLAN tags when
Switch A sends packets to Switch B.
-VLAN
SER