Gvrp, Gvrp overview, Guidelines – Allied Telesis AT 8000/8POE User Manual
Page 131: Gvrp overview guidelines, Figure 32. gvrp example

AT-S81 Management Software User’s Guide
Section I: Using the Menus Interface
131
GVRP
This section describes GVRP and contains the following topics:
“Enabling or Disabling GVRP” on page 132
GVRP Overview
The GARP VLAN Registration Protocol (GVRP) allows network devices to
share VLAN information. The main purpose of GVRP is to allow switches
to automatically discover some of the VLAN information that would
otherwise need to be manually configured in each switch. This is helpful in
networks where VLANs span more than one switch. Without GVRP, you
must manually configure your switches to ensure that the various parts of
a VLAN can communicate across the different switches. GVRP, which is
an application of the Generic Attribute Registration Protocol (GARP), does
this for you automatically.
Figure 32 provides an example of how the GVRP feature works:
Figure 32. GVRP Example
Switches 1 and 3 contain the Sales VLAN, but switch 2 does not.
Consequently, the end nodes of the two parts of the Sales VLANs are
unable to communicate with each other.
Without GVRP, you would need to configure switch 2 by creating a Sales
VLAN on the switch and adding ports 2 and 3 as members of the VLAN. If
you have a large network and a large number of VLANS, this type of
manual configuration can be cumbersome and time consuming. Instead,
let GVRP set up the communications path for you.
Guidelines
Following are guidelines to observe when you use GVRP:
Both ports that constitute a data link between the
switch and the other device must be running GVRP.
You cannot modify a GVRP VLAN; you can only
enable or disable it.