112 CHAPTER 7: GVRP CONFIGURATION
■Leave: When a GARP entity expects to unregister a piece of attribute information,
it sends out a Leave message. Any GARP entity receives this message starts its
Leave timer, and unregister the attribute information after the timer times out if it
does not receives a Join message again before the timeout.
■LeaveAll: Once a GARP entity starts up, it starts the LeaveAll timer, and sends out a
LeaveALL message after the timer times out, so that other GARP entities can
re-register all the attribute information on this entity. After that, the entity restarts
the LeaveAll timer to begin a new cycle.
GVRP port registration mode
GVRP has the following port registration modes:
■Normal: In this mode, both dynamic and manual creation, registration and
unregistration of VLAN are allowed.
■Fixed: In this mode, when you created a static VLAN on a switch and the packets
of this VLAN are allowed to pass through the current port, the switch joins the
current port to this VLAN and add a VLAN entry to the local GVRP database (a
table maintained by GVRP); but GVRP cannot learn dynamic VLAN through this
port, and the dynamic VLANs learned through other ports on this switch cannot
be pronounced through this port.
■Forbidden: In this mode, all the VLANs except VLAN 1 are unregistered on the
port, and no other VLANs can be created or registered on the port.
GARP operation procedure
Through the working scheme of GARP, the configuration information on a GARP
member will be propagate to the whole switching network. A GARP can be a
terminal workstation or a bridge; it informs other GARP member to register/unregister
its attribute information by declaration/recant, and register/unregister other GARP
member's attribute information according to other member's declaration/recant.
The protocol packets of GARP entity use specific multicast MAC addresses as their
destination MAC addresses. When receiving these packets, the switch distinguishes
them packet by their destination MAC addressed and delivers them to different GARP
application (for example, GVRP) for further processing.