HP A5120 EI Series Configuration Guide

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GVRP configuration
The Generic Attribute Registration Protocol (GARP) provides a generic framework for devices in a bridged
LAN, such as end stations and switches, to register and deregister attribute values. The GARP VLAN
Registration Protocol (GVRP) is a GARP application that registers and deregisters VLAN attributes. GVRP
uses the operating mechanism of GARP to maintain and propagate dynamic VLAN registration
information for GVRP devices on the network.
Introduction to GVRP
GARP
GARP provides a mechanism that allows participants in a GARP application to distribute, propagate, and
register—with other participants in a LAN—the attributes specific to the GARP application, such as the
VLAN or multicast address attributes.
How GARP works
Each port that participates in a GARP application (GVRP, for example) is a GARP participant.
Through the GARP mechanism, the attribute information of GARP participants is rapidly propagated
across the entire LAN. A GARP participant registers and deregisters its attribute information with other
GARP participants by sending and withdrawing declarations, and registers and deregisters the attribute
information of other participants according to the declarations and withdrawals that it receives.
Figure 44 How GARP works
Device A
Device B
Declaration
De-register
Register
Declaration withdrawal
For example, GVRP registers and deregisters VLAN attributes in the following cases.
 When a port receives a declaration for a VLAN attribute, it registers the VLAN attribute carried in
the declaration and joins the VLAN.
 When a port receives a withdrawal for a VLAN attribute, it deregisters the VLAN attribute carried in
the withdrawal and leaves the VLAN.
GARP messages
A GARP participant exchanges information with other GARP participants by sending GARP messages,
which are Join, Leave, and LeaveAll. These messages work together to ensure the registration and
deregistration of attribute information. As a GARP application, GVRP also uses GARP messages for
information exchange.

HP A5120 EI Series Specifications

General

Uplink Ports	4 x SFP
Stacking	No
Management	CLI, Web, SNMP
Routing Protocols	RIP, OSPF
Power Supply	AC
MAC Address Table Size	16K
Dimensions	440 x 430 x 44 mm
Operating Temperature	0°C to 45°C
Operating Humidity	10% to 90% non-condensing
Model	HP A5120-24G EI Switch (JG234A)
VLANs	4094