R2511-HP MSR Router Series Layer 2 - LAN Switching Configuration Guide(V5)

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Figure 32 GARP PDU format
Table 16 describes the usage and values of fields contained in the GARP PDU portion of the Ethernet
frames.
Table 16 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
Attribute value Attribute value.
VLAN ID for GVRP.
If the value of the Attribute event field is
0x00 (LeaveAll event), the Attribute value
field is invalid.
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