Allied Telesis AT-S62 - Manual (Page 586)

Chapter 25: GARP VLAN Registration Protocol
586 Section V: VLANs
GVRP-inactive
Intermediate
Switches
The presence of a GVRP-inactive switch between GVRP-active devices
may impact the ability of GVRP to automatically configure the VLANs in
your switches. You might need to take this into account when
implementing GVRP in your network.
One of the problems posed by the introduction of a GVRP-inactive device
is that a GVRP-inactive device will probably not forward PDUs, thus
preventing the GVRP-active switches from sharing VLAN information.
PDUs are management packets, intended for a switch’s CPU. In all
likelihood, a GVRP-inactive switch will discard the PDUs it receives on its
ports because the CPU will not recognize their function.
Another issue is that even if the GVRP-inactive switch does forward
GVRP PDUs, it will not automatically create the VLANs. Consequently,
even if GVRP-active switches on either side of a GVRP-inactive switch
receive the PDUs and create the necessary VLANs, the intermediate
switch may block the VLAN traffic, unless you manually modify its VLANs
and port assignments.