Owner manual

VLANs and Your Switch 165
VLANs and Your
Switch
Your Switch provides the following VLAN features:
■
Support for up to 16 VLANs using the IEEE 802.1Q standard
The IEEE 802.1Q standard allows each port on your Switch to:
■
Be placed in any single VLAN defined on the Switch.
■
Be placed in several VLANs at the same time using 802.1Q tagging.
■
Use 802.1Q learning — A system that uses the GARP VLAN
Registration Protocol (GVRP) to enable the Switch to learn the
VLAN requirements of the endstations attached to each port, and
place the relevant ports in those VLANs automatically.
■
Forward traffic for VLANs that are unknown to the Switch.
The standard requires that you define the following information about
each VLAN on your Switch before the Switch can use it to forward
traffic:
■
VLAN Name
— This is a descriptive name for the VLAN (for
example, Marketing or Management).
■
802.1Q VLAN ID
— This is used to identify the VLAN if you use
802.1Q tagging across your network.
■
Local ID
— This is used to identify the VLAN within the Switch, and
corresponds to the VLAN IDs used in legacy 3Com devices.
■
Support for VLT tagging
VLT (Virtual LAN Trunk) tagging is a proprietary 3Com system that
allows a port to be placed in all the VLANs defined for your Switch.
The Default VLAN
A new or initialized Switch contains a single VLAN, the Default VLAN.
This VLAN has the following definition:
■
VLAN Name
— Default VLAN
■
802.1Q VLAN ID
— 1
■
Local ID
— 1
All the ports are initially placed in this VLAN, and it is the only VLAN that
allows you to access the management software of the Switch over the
network.