Garp Vlan Registration Protocol (Gvrp); Important Considerations - 3Com corebuilder 3500 Implementation Manual

GARP VLAN
Registration
Protocol (GVRP)
Important
Considerations
To activate GVRP on the system, you enable the GARP VLAN Registration
Protocol (GVRP) first on the bridge and then on individual bridge ports.
On a port-by-port basis, GVRP allows the system to automatically learn
the presence of and updates to 802.1Q VLANs. GVRP simplifies the
management of IEEE 802.1Q VLAN configurations in large networks by
making aspects of VLAN configuration dynamic.
GVRP maintains a database of VLAN member ports as the bridge learns
about them. Specifically, GVRP tracks which ports are added to and
removed from each VLAN and communicates this information to other
GVRP-aware bridges. The bridges then determine active topologies for
the network and for each VLAN using STP to prevent network loops.
GVRP operates only on ports that are in the STP forwarding state. If GVRP
is enabled, a port that changes to the STP forwarding state automatically
begins to participate in GVRP. A port that changes to an STP state other
than forwarding no longer participates in GVRP. For more information
about GVRP and VLANs, see Chapter 9.
To use GVRP, consider the following:
GVRP updates are not sent out to any blocked STP ports. GVRP
operates only on ports that are in the STP forwarding state.
GVRP is disabled by default on the bridge and on all bridge ports.
Enabling GVRP determines whether the VLAN origin for a port-based
VLAN is dynamic (GVRP enabled) or static (GVRP disabled).
To maximize the effectiveness of GVRP, it should be supported in as
many end stations and network devices as possible.
Based on updates from GVRP-enabled devices, GVRP allows the
system to dynamically create a port-based VLAN (unspecified protocol)
with a specific VLAN ID and a specific port.
On a port-by-port basis, GVRP allows the system to learn about GVRP
updates to an existing port-based, protocol-based, or network-based
VLAN with that VLAN ID and IEEE 802.1Q tagging.
VLANs that are created dynamically with GVRP exist only as long as a
GVRP-enabled device is sending updates — if the devices no longer
send updates, or if GVRP is disabled, or if the system is rebooted, all
dynamic VLANs are removed.

GARP VLAN Registration Protocol (GVRP)

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