H3C Technologies H3C S12500 Series Switches - Manual (Page 184)

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Configuring GVRP
The Generic Attribute Registration Protocol (GARP) provides a generic framework whereby devices in a
bridged LAN, such as end stations and switches, can 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 the GVRP devices on the network.
Overview
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. As shown in Figure 60 , 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
it receives.
Figure 60 How GARP works
For example, GVRP registers and deregisters VLAN attributes as follows:
• 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,
including Join, Leave, and LeaveAll. These messages work together to ensure the registration and