Administrator Guide

GARP VLAN Registration Protocol (GVRP)
GARP VLAN registration protocol (GVRP), defined by the IEEE 802.1q specification, is a Layer 2 network protocol that provides for
automatic VLAN configuration of switches. GVRP-compliant switches use GARP to register and de-register attribute values, such as
VLAN IDs, with each other.
Typical virtual local area network (VLAN) implementation involves manually configuring each Layer 2 switch that participates in a given
VLAN. 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, the edge ports must still be statically configured 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.
Dell(conf)#protocol spanning-tree pvst
Dell(conf-pvst)#no disable
% Error: GVRP running. Cannot enable PVST.
.........
Dell(conf)#protocol spanning-tree mstp
Dell(conf-mstp)#no disable
% Error: GVRP running. Cannot enable MSTP.
.........
Dell(conf)#protocol gvrp
Dell(conf-gvrp)#no disable
% Error: PVST running. Cannot enable GVRP.
% Error: MSTP running. Cannot enable GVRP.
Topics:
• Configure GVRP
• Enabling GVRP Globally
• Enabling GVRP on a Layer 2 Interface
• Configure GVRP Registration
• Configure a GARP Timer
Configure GVRP
To begin, enable GVRP.
To facilitate GVRP communications, enable GVRP globally on each switch. 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,
GVRP is configured on VLAN trunk ports.
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370 GARP VLAN Registration Protocol (GVRP)