Huawei S Series - Istack Packet Forwarding; Unicast Packet Forwarding

S Series Switches
iStack Technology White Paper
2 Technology Description
Issue 01 (2013-05-25)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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2.12 iStack Packet Forwarding
2.12.1 Unicast Packet Forwarding
Unicast stack packets are forwarded in the following situations:

Unicast stack packets are forwarded within the local device without being forwarded
over stack links, as shown in Figure 2-22.

Unicast stack packets need to be forwarded from the slave switch to the standby switch.
Because there is no direct link between the two switches, the packets need to be
forwarded by the master switch, as shown in Figure 2-23. This forwarding mode
occupies bandwidth between the master and slave switches and between the master and
standby switches.

In the ring topology shown in Figure 2-24, unicast stack packets from the slave switch to
the standby switch are forwarded according to the shortest path. This forwarding mode
does not occupy bandwidth between the master and slave switches and between the
master and standby switches.
Figure 2-22 Intra-device unicast packet forwarding
Master
Slave Standby
Figure 2-23 Inter-device unicast packet forwarding in a chain topology
Master
Slave
Standby