3Com Switch 8800 Advanced Software V5 Configuration Guide

PORT ISOLATION CONFIGURATION

When configuring port isolation, go to these sections for information you are

interested in:

■ “Introduction to Port Isolation” on page 177

■ “Configuring Isolation Groups on a Device” on page 178

■ “Displaying Isolation Groups” on page 179

■ “Port Isolation Configuration Example” on page 179

Introduction to Port

Isolation

To implement Layer 2 isolation, you can add different ports to different VLANs.

However, this will waste the limited VLAN resource. With port isolation, the ports

can be isolated within the same VLAN. Thus, you need only to add the ports to the

isolation group to implement Layer 2 isolation. This provides you with more secure

and flexible networking schemes.

To enable the interconnection between an isolation group and Layer 2 outside the

isolation group, you must configure an uplink port for the isolation group. The last

configuration will overwrite the previous configurations if you configure different

ports as the uplink port.

■ Layer 2 traffic can pass from the ports in the isolation group to the uplink port.

■ To enable the Layer 2 traffic to pass from the uplink port to the port in a certain

isolation group, you must configure these two ports to be in the same VLAN.

At present, for the Switch 8800 Families:

■ A maximum of 64 isolation groups can be configured.

■ There is no restriction on the number of ports to be added to an isolation

group.

■ When a port in the summary group is configured as the ordinary port for some

isolation group, the other ports of the summary group can be added to the

isolation group as ordinary ports but cannot be configured as uplink ports.

■ When a port in the summary group is configured as the uplink port for some

isolation group, the other ports of the summary group cannot be added to the

isolation group and the other ports of the device cannot be added to the

summary group.

■ The port isolation feature only isolates Layer 2 data instead of Layer 3 data.

Port isolation is independent of the VLAN the port belongs to. For ports belonging

to different VLANs, Layer 2 data can pass only from the ordinary port to the uplink

port in the same isolation group unidirectionally. Within the same VLAN, there are