The Generic Attribute Registration Protocol (GARP) is a protocol for registering attributes. It is defined in IEEE 802.1d and is used by end devices in local area networks( LAN) to transmit their attributes to switches or bridges. End device attributes include membership in a multicast group or in a Virtual LAN( VLAN). The GARP VLAN Registration Protocol( GVRP) exists for dynamic assignment of VLAN end devices.
The switches in local networks learn and register the attributes of the end devices that these transmit to them. Only after registering the attributes are they registered and receive targeted data packets from the switch. In meshed network structures, all other stations register the registered attributes, which builds up a unique path for the registered services and stations.
The GARP protocol is a port-oriented protocol, with ports exchanging their information with the GIP protocol. From the frame structure, the GARP protocol consists of the protocol ID and the message part that contains the individual attributes. In these data fields the attribute type and the individual attributes are defined. The attribute types are distinguished between group and service attributes. The end of the message field is defined by an end mark field.
The GARP protocol has been replaced by the Multiple Registration Protocol( MRP).