Foundry NetIron M2404C and M2404F Metro Access Switches Configuring VLANs (Rev.03)
GARP VLAN Registration Protocol (GVRP)
© 2008 Foundry Networks, Inc.
Page 64 of 73
Figure 17: GVRP Example
The GARP Timers
The GARP is designed to provide a generic framework whereby devices in a bridged LAN, can
register and de-register attribute values, such as VLAN Identifiers, with each other. In doing so, the
attributes are propagated to devices in the bridged LAN, and these devices form a “reachability”
tree that is a subset of an active topology.
The GVRP is one of the GARP applications. The purpose of GVRP is to propagate VLAN
information between VLAN-aware switches.
The Join Timer
The
join
timer sets the duration of the Join Period timer for the GARP applications in milliseconds.
The timer controls the interval between opportunities to transmit GARP PDUs.
The Leave Timer
The
leave
timer sets the duration of the Leave Period timer for the GARP applications in
milliseconds. The timer controls the period of time that the registrar state machine will wait in the
LV (Leave) state before entering the MT (Empty) state, i.e. how long a registrar will wait for a Join
message before de-registering an attribute from the registered IN state. Each port in the GARP
application has a single Leave Period timer.
The LeaveAll Timer
The
leaveall
timer sets the duration of the LeaveAll Period timer for the GARP application in
milliseconds. The timer controls the frequency at which the LeaveAll state machine generates a
LeaveAll message in a GARP PDU, and refreshes its database.
The Criteria for Setting the GARP Timers
The two criteria for setting the timers are:
1. LEAVETIME >= JOINTIME * 3
(as specified in IEEE standard 802.1D).
2. The LeaveAll Period must be significantly greater than the Leave Period, as specified in
the IEEE standard.
To change the GARP timers, use the
garp timer
command in Protocol Configuration mode.
GVRP Default Configuration
Table 14
shows the GVRP default configuration.