White Papers

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.
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. 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 VLAN trunk port, but it is not necessary to specifically identify to the
Dell Networking OS that the port is a trunk port.
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334 GARP VLAN Registration Protocol (GVRP)