GARP VLAN Registration Protocol (GVRP) | 20511GARP VLAN Registration Protocol (GVRP)This chapter contains the following sections:• Configuring GVRP• Enabling GVRP Globally• Enabling GVRP on a Layer 2 Interface• Configuring GVRP Registration• Configuring a GARP TimerOverviewTypical virtual local area network (VLAN) implementation involves manually configuring each Layer 2switch that participates in a given VLAN. GARP VLAN registration protocol (GVRP), defined by theIEEE 802.1q specification, is a Layer 2 network protocol that provides for automatic VLAN configurationof switches. GVRP-compliant switches use the generic attribute registration protocol (GARP) to registerand 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 ormore VLANs. Consequently, GVRP spreads this information and configures the needed VLAN(s) on anyadditional switches in the network. Data propagates using the exchange of GVRP protocol data units(PDUs).The purpose of GVRP is to simplify (but not eliminate) static configuration. The idea is to configureswitches at the edge and have the information dynamically propagate into the core. As such, the edge portsmust still be statically configured with VLAN membership information, and they do not run GVRP. It isthis 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 switchesto 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 tothe other active ports.• GVRP is disabled by default; you must enable GVRP for the switch and then for individual ports.
