3Com 5500-SI 7

7GVRP CONFIGURATION

This chapter contains GVRP configuration information.

Introduction to GVRP GVRP (GARP VLAN Registration Protocol) is an application of GARP (Generic Attribute

Registration Protocol). GVRP is based on the work scheme of GARP; it maintains

dynamic VLAN registration information and propagates the information to other

switches.

GARP is a generic attribute registration protocol. This protocol provides a scheme to

and so on, between the switching members in a switching network

After the GVRP feature is enabled on a switch, the switch can receive the VLAN

registration information from other switches to dynamically update the local VLAN

registration information (including current VLAN members, which ports these VLAN

members get to), and propagate the local VLAN registration information to other

switches so that all the switching devices in the same switching network can have the

same VLAN information. The VLAN registration information not only includes the

static registration information configured locally, but also includes the dynamic

registration information from other switches.

GVRP Working Scheme GARP Timers

The information exchange between GARP members is completed by messages. The

messages performing important functions for GARP fall into three types: Join, Leave

and LeaveAll.

■When a GARP entity expects other switches to register certain attribute

information of its own, it sends out a Join message.

■When a GARP entity expects other switches to unregister certain attribute

information of its own, it sends out a Leave message.

■Once a GARP entity starts up, it starts the LeaveAll timer. After the timer times out,

the GARP entity sends out a LeaveAll message.

The join message and the Leave message are used together to complete the

unregistration and re-registration of information. Through message exchange, all the

attribute information to be registered can be propagated to all the switches in the

same switching network.

GARP has the following timers:

■Hold: When a GARP entity receives a piece of registration information, it does not

send out a Join message immediately. Instead, it starts the Hold timer, and sends

out a Join message after the timer times out, so that all the registration

information received before the timer times out can be put into the same frame

that will be sent to save the bandwidth resources.

■Join: After the Join timer times out, the GARP entity sends out a Join message to

indicate other GARP entities to register the information of its own.