3Com Switch 7750 Configuration Guide

Introduction to GARP and GVRP 155
distinguishes them by their destination MAC addresses and delivers them to
different GARP application (for example, GVRP) for further processing.
GVRP Packet Format The GVRP packets are in the following format:
Figure 41 Format of GVRP packets
The following table describes the fields of a GVRP packet.
Table 94 Description of GVRP packet fields
Field Description Value
Protocol ID Protocol ID 1
Message Each message consists of two parts:
Attribute Type and Attribute List.
-
Attribute Type Defined by the specific GARP
application
The attribute type of GVRP is
0x01.
Attribute List It contains multiple attributes. -
Attribute 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.
-
Attribute Length The length of the attribute 2 to 255
Attribute Event The event described by the attribute 0: LeaveAll Event
1: JoinEmpty
2: JoinIn
3: LeaveEmpty
4: LeaveIn
5: Empty
Attribute Value The value of the attribute The attribute value of GVRP is the
VID.
GARP PDU structure
Message structure
Attribute List structure
Attribute structure
Protocol ID Message N End Mark...
Attribute 1 End Mark...
Attribute Type
Attribute Length Attribute Event Attribute Value
1
1
1
1
3
3
2
2
N
N
N
N
Message 1
Attribute List
Attribute N
PDUDA length DSAPSA CtrlSSAP Ethernet Frame