H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 129)

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H3C's implementation of GARP uses the following timers to control GARP message transmission:
1. Hold timer
The Hold timer sets the delay that a GARP participant waits before sending a Join or Leave message.
When an attribute value changes or a Join or Leave message arrives, the GARP participant does not
send the message immediately. Rather, it assembles Join and Leave messages in the least number of
GARP PDUs, and sends them out when the Hold timer expires. This timer reduces the number of GARP
PDUs and saves bandwidth.
2. Join timer
A GARP participant may declare an attribute twice to ensure reliable transmission. The Join timer sets the
interval between the two declarations.
A GARP participant starts a Join timer when it declares an attribute value or receives a JoinIn message
for the attribute value. If the GARP participant does not receive any declaration for the attribute value
when the Join timer expires, it re-declares the attribute value.
NOTE:
Because all attributes of a GARP participant share the same Join timer, you must set the Join timer long
enough so that all attributes can be sent out in one declaration.
3. Leave timer
A GARP participant starts a Leave timer when it receives a Leave message for an attribute value. If the
GARP participant has not received a Join message for the attribute value before the timer expires, it
deregisters the attribute value.
4. LeaveAll timer
When a GARP application is enabled, a LeaveAll timer starts. The GARP participant sends a LeaveAll
message when the timer expires. Then, the LeaveAll timer restarts to begin a new cycle. The LeaveAll
timer and all other GARP timers also restart when the GARP participant receives a LeaveAll message.
NOTE:
•
Set the LeaveAll timer greater than any Leave timer because each time a LeaveAll timer expires, a
network-wide re-join occurs.
• A device may send LeaveAll messages at the interval set by its LeaveAll timer or the LeaveAll timer on
another device on the network, whichever is smaller. This is because each time a device on the network
receives a LeaveAll message it resets its LeaveAll timer.