H3C SR8800 Configuration Manual page 118

Join messages
1.
A GARP participant sends Join messages when it wants to register its attributes (including manually
configured attributes) on other participants, and when it receives Join messages from other
participants. There are two types of Join messages: JoinEmpty and JoinIn.
A GARP participant sends a JoinEmpty message to declare an attribute not registered on it.
A GARP participant sends a JoinIn message to declare an attribute registered on it.
Leave messages
2.
A GARP participant sends Leave messages to have its attributes deregistered on other participants.
It also sends Leave messages when it deregisters attributes after receiving Leave messages from
other GARP participants, and when attributes are manually deregistered on it. There are two types
of Leave messages: LeaveEmpty and LeaveIn.
A GARP participant sends a LeaveEmpty message to deregister an attribute not registered on
it.
A GARP participant sends a LeaveIn message to deregister an attribute registered on it.
LeaveAll messages
3.
Each GARP participant starts a LeaveAll timer upon startup. Upon the expiration of the LeaveAll
timer, a GARP participant sends LeaveAll messages to deregister all attributes so that all attributes
can be re-registered on the other GARP participants. When a GARP participant receives LeaveAll
messages from other GARP participants, it also sends LeaveAll messages and reset the LeaveAll
timer.
GARP timers
NOTE:
The settings of GARP timers apply to all GARP applications, such as GVRP, on a LAN.
•
On a GARP-enabled network, each port of a network device maintains its own Hold, Join, and Leave
•
timers, but only one LeaveAll timer is maintained on each device globally.
The value ranges for the Hold, Join, Leave, and LeaveAll timers are dependent on one another. For more
•
information, see
GARP defines the following timers to control the sending of GARP messages:
Hold timer
1.
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 sends 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.
Join timer
2.
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.
Table 16.
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