Garp pdu format – H3C Technologies H3C S10500 Series Switches User Manual

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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.

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 and not smaller than its default value, 1000
centiseconds. Each time a LeaveAll timer expires, a network-wide re-join occurs.

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.

GARP PDU format

Figure 52 GARP PDU format

As shown in

Figure 52

, GARP PDUs are encapsulated in IEEE 802.3 Ethernet frames.

Table 19 GARP PDU fields

Field Description

Value

Protocol ID

Protocol identifier for GARP

0x0001

Message

One or multiple messages, each of which
contains an attribute type and an attribute

list

––

End mark

Indicates the end of a GARP PDU

0x00

Attribute type

Defined by the GARP application

0x01 for GVRP, which indicates the VLAN
ID attribute

Attribute list

Contains one or multiple attributes

––

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