Administrator Guide

GARP VLAN Registration Protocol

(GVRP)

Dell Networking OS supports 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. GVRP-compliant switches use GARP to

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.

• On the Switch, you cannot enable per-VLAN spanning tree+ (PVST+) and GVRP at the same time. If

spanning tree and GVRP are both required, implement either rapid spanning tree protocol (RSTP),

spanning tree protocol (STP), or multiple spanning tree protocol (MSTP). Dell Networking OS does

support enabling GVRP and MSTP at the same time.

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.

Topics:

GARP VLAN Registration Protocol (GVRP) 372