R3303-HP HSR6800 Routers Layer 2 - LAN Switching Configuration Guide

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GARP PDU format
As shown in Figure 47, GARP PDUs are encapsulated in IEEE 802.3 Ethernet frames.
Figure 47 GARP PDU format
Table 17 describes the usage and values of fields contained in the GARP PDU portion of the Ethernet
frames.
Table 17 GARP PDU fields
Field Descri
p
tion Value
Protocol ID Protocol identifier for GARP. 0x0001.
Message
One or multiple messages, each containing
an attribute type and an attribute list.
N/A
End mark Indicates the end of a GARP PDU. 0x00.
Attribute type Defined by the GARP application.
0x01 for GVRP, indicating the VLAN ID
attribute.
Attribute list Contains one or multiple attributes. N/A
Attribute
Consists of an Attribute Length, an Attribute
Event, and an Attribute Value.
N/A
Attribute length
Length of an attribute, inclusive of the
attribute length field.
2 to 255 (in bytes).
Attribute event Event described by the attribute.
• 0x00—LeaveAll event
• 0x01—JoinEmpty event
• 0x02—JoinIn event
• 0x03—LeaveEmpty event
• 0x04—LeaveIn event
• 0x05—Empty event
Ethernet frame
Attribute length Attribute event Attribute value
DA SA Length DSAP SSAP Ctrl GARP PDU
Attribute listAttribute type
... Message nMessage 1Protocol ID End mark
...Attribute 1 Attribute n End mark