Operation Manual – GVRP
H3C S9500 Series Routing Switches
Chapter 1 GVRP Configuration
1-3
In GARP, a GARP participant registers or deregisters its attributes with other
participants by making or withdrawing declarations of attributes and at the same time,
based on received declarations or withdrawals, registers or deregisters the attributes of
other participants.
GARP application entities send protocol data units (PDU) with a particular multicast
MAC address as destination. Based on this address, a device can identify to which
GVRP application, GVRP for example, a GARP PDU should be delivered.
III. GARP message format
The following figure illustrates the format of GARP messages, which are carried in
GARP PDUs.
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 Vlaue
1
1
1
1
3
3
2
2
N
N
N
N
Message 1
Attribute List
Attribute N
Figure 1-1
GARP message format
The following table describes the GARP message fields.
Table 1-1
Description on the GARP message fields
Field
Description
Value
Protocol ID
Protocol identifier for GARP
1
Message
Each message contains an
attribute type and an attribute list
––
Attribute Type
Defined by the concerned GARP
application
0x01 for GVRP, indicating
the VLAN ID attribute
Attribute List
Contains one or multiple
attributes
––
Attribute
Consists of an Attribute Length,
an Attribute Event, and an
Attribute Value
––
Attribute Length
Number of octets occupied by an
attribute, inclusive of the attribute
length field
2 to 255 in bytes
