3Com 4210 9-Port Configuration Manual page 122

Figure 1-1 Format of GARP packets
The following table describes the fields of a GARP packet.
Table 1-1 Description of GARP packet fields
Field
Protocol ID
Message
Attribute Type
Attribute List
Attribute
Attribute Length
Attribute Event
Attribute Value
End Mark
Description
Protocol ID
Each message consists of two parts:
Attribute Type and Attribute List.
Defined by the specific GARP
application
It contains multiple attributes.
Each general attribute consists of
three parts: Attribute Length,
Attribute Event, and Attribute Value.
Each LeaveAll attribute consists of
two parts: Attribute Length and
LeaveAll Event.
The length of the attribute
The event described by the attribute
The value of the attribute
End mark of an GARP PDU
1-3
Value
1
—
The attribute type of GVRP is 0x01.
—
—
2 to 255 (in bytes)
0: LeaveAll Event
1: JoinEmpty
2: JoinIn
3: LeaveEmpty
4: LeaveIn
5: Empty
For GVRP packets, the value of this
field is the VLAN ID; however, for
LeaveAll messages, this field is
invalid.
The value of this field is fixed to
0x00.