3Com Switch 7750 Configuration Guide

924 CHAPTER 84: SMART LINK CONFIGURATION
Slave port
The slave port can be either an Ethernet port or a manually-configured or static
LACP aggregation group. For example, you can configure Ethernet2/0/2 of switch
A in Figure 256 as the slave port through the command line.
Flush message
When a forwarding link fails, the device will switch the traffic to the blocked
standby link. The former forwarding entries of each device in the network are no
longer suitable for the new topology, so MAC address forwarding entries and ARP
entries must be updated throughout the network. In this case, the Smart Link
group sends flush messages to notify other devices to refresh MAC address
forwarding entries and ARP entries.
Control VLAN for sending flush messages
This control VLAN sends flush messages. When link switching occurs, the device
(Switch A in Figure 256) broadcasts flush messages in this control VLAN.
Control VLAN for receiving flush messages
This control VLAN is used for receiving and processing flush messages. When link
switching occurs, the devices (Switch B and Switch C in Figure 256) receive and
process flush messages of this control VLAN, and then refresh MAC forwarding
table entries and ARP entries.
n
■ Currently, the member ports of a Smart Link group cannot be dynamic link
aggregation groups.
■ If the master port or slave port of a Smart Link group is a link aggregation
group, you cannot remove this link aggregation group directly or change the
aggregation group into a dynamic aggregation group. Before removing this
aggregation group, you must unbind the link aggregation group from the
Smart Link.
Operating Mechanism of
Smart Link
Figure 257 Network diagram of Smart Link operating mechanism
BLOCK
Switch A Switch B
Eth1/0/1
Eth1/0/2
Switch C Switch D
Switch E
Eth1/0/1
Eth1/0/2
Eth1/0/3
Eth1 /0/1
Eth1/0/2
Eth1 /0/11
Eth1 /0/12