GARP VLAN Registration Protocol (GVRP)The generic attribute registration protocol (GARP) VLAN registration protocol (GVRP), defined by the IEEE 802.1q specification, is a Layer2 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 givenVLAN. GVRP, defined by the IEEE 802.1q specification, is a Layer 2 network protocol that provides for automatic VLAN configuration ofswitches. 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, GVRPspreads this information and configures the needed VLANs on any additional switches in the network. Data propagates via the exchange ofGVRP 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 theinformation dynamically propagate into the core. As such, the edge ports must still be statically configured with VLAN membershipinformation, and they do not run GVRP. It is this information that is propagated to create dynamic VLAN membership in the core of thenetwork.Important Points to Remember• GVRP propagates VLAN membership throughout a network. GVRP allows end stations and switches to issue and revoke declarationsrelating 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 theshow gvrp statistics {interface interface | summary} command.Dell(conf)#protocol spanning-tree pvstDell(conf-pvst)#no disable% Error: GVRP running. Cannot enable PVST..........Dell(conf)#protocol spanning-tree mstpDell(conf-mstp)#no disable% Error: GVRP running. Cannot enable MSTP..........Dell(conf)#protocol gvrpDell(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 Timer17332 GARP VLAN Registration Protocol (GVRP)
