After receiving a LeaveAll message, a participant restarts all GARP timers. The participant
sends another LeaveAll message when its LeaveAll timer expires. This reduces LeaveAll
messages sent in a period of time.
If LeaveAll timers of multiple devices expire at the same time, they send LeaveAll messages
at the same time, which causes unnecessary LeaveAll messages. To solve this problem,
each device uses a random value between the LeaveAll timer value and 1.5 times the
LeaveAll timer value as its LeaveAll timer value. When a LeaveAll event occurs, all
attributes on the entire network are deregistered. The LeaveAll event affects the entire
network; therefore, you need to set the LeaveAll timer to a proper value, at least greater
than the Leave timer value.
Each device maintains a global LeaveAll timer.
Registration Modes
A manually configured VLAN is a static VLAN, and a VLAN created through GVRP is a
dynamic VLAN. GVRP provides three registration modes. Static VLANs and dynamic VLANs
are processed differently in each registration mode as follows:
l
Normal mode: Dynamic VLANs can be registered on a port, and the port can send
declarations of static VLANs and dynamic VLANs.
l
Fixed mode: Dynamic VLANs cannot be registered on a port, and the port can send only
declarations of static VLANs.
l
Forbidden mode: Dynamic VLANs cannot be registered on a port. All VLANs except
VLAN 1 are deleted from the port, and the port can send only the declaration of VLAN 1.
5.2.2 Packet Structure
GARP packets are encapsulated in the IEEE 802.3 Ethernet format, as shown in
Figure 5-4
GARP packet structure
DA SA length DSAP SSAP Ctrl
PDU
Protocol ID Message 1
…
Message N End Mark
Attribute Type
Attribute List
Attribute 1
End Mark
Attribute N
…
Attribute Length Attribute Event Attribute Value
Ethernet Frame
GARP PDU structure
1
1
1
1
N
N
N
N
3
2
2
3
Message structure
Attribute List structure
Attribute structure
The following table describes the fields in a GARP packet.
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
5 GVRP Configuration
Issue 01 (2014-11-30)
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