Huawei AR530 Series - Page 165

One-Way Deregistration
Figure 5-7 One-way deregistration of a VLAN attribute
RouterA
RouterB
RouterC
Port 2
Port 1
Port 3
Port 4
LeaveEmpty
LeaveIn
Static vlan 2
When VLAN 2 is not required on the routers, the routers can deregister VLAN 2. The process
is as follows:
1. After static VLAN 2 is manually deleted from RouterA, Port 1 of RouterA starts the Hold
timer. When the Hold timer expires, Port 1 sends a LeaveEmpty message to RouterB. Port
1 needs to send only one LeaveEmpty message.
2. After Port 2 of RouterB receives the LeaveEmpty message, it starts the Leave timer. When
the Leave timer expires, Port 2 deregisters VLAN 2. Then Port 2 is deleted from VLAN 2,
but VLAN 2 is not deleted from RouterB because Port 3 is still in VLAN 2. At this time,
RouterB requests Port 3 to start the Hold timer and Leave timer. When the Hold timer
expires, Port 3 sends a LeaveIn message to RouterC. Static VLAN 2 is not deleted from
RouterC; therefore, Port 3 can receive the JoinIn message sent from Port 4 after the Leave
timer expires. In this case, RouterA and RouterB can still learn dynamic VLAN 2.
3. After RouterC receives the LeaveIn message, Port 4 is not deleted from VLAN 2 because
VLAN 2 is a static VLAN on RouterC.
Two-Way Deregistration
Figure 5-8 Two-way deregistration of a VLAN attribute
RouterA
RouterB
RouterC
Port 2
Port 1
Port 3
Port 4
LeaveEmpty
LeaveEmpty
LeaveEmpty
LeaveIn
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching 5 GVRP Configuration
Issue 01 (2014-11-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
151