Unknown Unicast And Broadcast Packet Forwarding - Huawei S Series White Paper

S Series Switches
iStack Technology White Paper
Figure 2-24 Inter-device unicast packet forwarding in a ring topology

2.12.2 Unknown Unicast and Broadcast Packet Forwarding

In a ring topology, broadcast packets will not be looped within a stack because the stack has
only one path. In a ring topology, loop prevention needs to be performed to prevent broadcast
packets from being looped between devices. The following describes how to prevent loops
when an even or odd number of member devices are deployed in a ring topology.
Loop Prevention in the Case of an Odd Number of Member Switches
In versions earlier than V200R001, the link farthest from the master switch is blocked to
prevent loops, as shown in Figure 2-25.
Figure 2-25 Broadcast packet forwarding in V100R006 and earlier versions
In versions earlier than V200R001, two users farther from the master need to communicate
and their data needs to be forwarded through stack cables of five member switches, as shown
in Figure 2-25. This forwarding mode wastes bandwidth of intermediate stack links.
Issue 01 (2013-05-25)
Slave
Standby
Master
Slave
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Master
Standby
2 Technology Description
Slave
Slave
31