HP 3100 Series Configuration Manual page 148

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Leave messages
A GARP participant sends Leave messages when it wishes to withdraw declarations of its
attribute values (because, for example, it has deregistered its attribute values), or receives
Leave messages from other participants.
Leave messages fall into LeaveEmpty and LeaveIn. A GARP participant sends LeaveEmpty
messages to withdraw declarations of the attribute values that it has not registered. It sends
LeaveIn messages to withdraw declarations of the attribute values that it has registered.
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LeaveAll messages
A GARP participant sends a LeaveAll message when it declares that it is deregistering all
attribute values or receives LeaveAll messages from other participants. If any participants want
to maintain the registration for a particular attribute value, they must send a Join message.
GARP timers
Hewlett Packard Enterprise's implementation of GARP uses the following timers to control GARP
message transmission:
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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.
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Join timer
A GARP participant might 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.
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.
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Leave timer
A GARP participant starts a Leave timer when it receives a Leave message for an attribute
value. If the GARP participant receives no Join message for the attribute value before the timer
expires, it deregisters the attribute value.
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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.
When you configure GARP timers, follow these guidelines:
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The settings of GARP timers apply to all GARP applications, such as GVRP, on a LAN.
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On a GARP-enabled network, each port maintains its own Hold, Join, and Leave timers, but
only one LeaveAll timer is maintained on each device. This LeaveAll timer applies to all ports on
the device.
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The value ranges for the Hold, Join, Leave, and LeaveAll timers are dependent on one another.
See Table 19
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Set the LeaveAll timer greater than any Leave timer and not smaller than its default value, 1000
centiseconds. Each time a LeaveAll timer expires, a network-wide re-join occurs.
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A device can send LeaveAll messages at the interval set by its LeaveAll timer or the LeaveAll
timer of 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.
for their dependencies.
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