Reference Guide

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GARP VLAN Registration Protocol (GVRP)
Typical virtual local area network (VLAN) implementation involves manually configuring each Layer 2
switch that participates in a given VLAN. GVRP, defined by the IEEE 802.1q specification, is a Layer 2
network protocol that provides for automatic VLAN configuration of switches. The GARP VLAN
registration protocol (GVRP)-compliant switches use GARP to register and de-register attribute values,
such as VLAN IDs, with each other.
GVRP exchanges network VLAN information to allow switches to dynamically forward frames for one or
more VLANs. Therefore, GVRP spreads this information and configures the needed VLANs on any
additional switches in the network. Data propagates via the exchange of GVRP protocol data units (PDUs).
The purpose of GVRP is to simplify (but not eliminate) static configuration. The idea is to configure
switches at the edge and have the information dynamically propagate into the core. As such, you must
statically configure the edge ports with VLAN membership information, and they do not run GVRP. It is
this information that is propagated to create dynamic VLAN membership in the core of the network.
Important Points to Remember
• GVRP propagates VLAN membership throughout a network. GVRP allows end stations and switches to
issue and revoke declarations relating to VLAN membership.
• VLAN registration is made in the context of the port that receives the GARP PDU and is propagated to
the other active ports.
• GVRP is disabled by default; enable GVRP for the switch and then for individual ports.
• Dynamic VLANs are aged out after the LeaveAll timer expires three times without receipt of a Join
message. To display status, use the show gvrp statistics {interface interface |
summary}
command.
• The S5000 supports Per-VLAN Spanning Tree (PVST+) and allows GVRP and MSTP to be enabled at
the same time.
Dell(conf)#protocol spanning-tree pvst
Dell(conf-pvst)#no disable
% Error: GVRP running. Cannot enable PVST.
.........
Dell(conf)#protocol gvrp
Dell(conf-gvrp)#no disable
% Error: MSTP running. Cannot enable GVRP.
Configure GVRP
To begin, enable GVRP.
To facilitate GVRP communications, enable GVRP globally on each switch. Then, GVRP configuration is
per interface on a switch-by-switch basis. Enable GVRP on each port that connects to a switch where
you want GVRP information exchanged. In the following example, that type of port is referred to as a
GARP VLAN Registration Protocol (GVRP)
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