Configuring Smart Link; Operating Mechanism Of Smart Link - 3Com 5500-EI PWR Install Manual

Operating Mechanism of Smart Link

Figure 1-2 Network diagram of Smart Link operating mechanism
Eth1/0/11
Switch E
Switch C
Eth1/0/1
Eth1/0/2
Eth1/0/3
Eth1/0/1
Eth1/0/2
Switch A
As shown in Figure
When the link connected to Ethernet 1/0/1 fails, Ethernet 1/0/1 is blocked automatically, and the state of
Ethernet 1/0/2 turns to active state.
When link switching occurs in the smart link group, MAC forwarding entries and ARP entries of
each device in the network may be out of date. In order to guarantee correct packet transmission,
you must enable the Smart Link device to send flush messages to notify the other devices in the
network to refresh their own MAC forwarding entries and ARP entries. In this case, all the uplink
devices must be capable of identifying flush messages from the smart link group and refreshing
MAC forwarding entries and ARP entries.
On a Smart Link–enabled device, if a port is blocked due to link failure, the port remains blocked
after the link recovers from the failure, and does not preempt the traffic resource. Therefore, the
traffic stays stable. The port does not come into the forwarding state until the next link switching.

Configuring Smart Link

Before configuring a member port of a smart link group, you must:
Disable the port to avoid loops, thus preventing broadcast storm.
Disable STP on the port.
After completing the configuration, you need to enable the Ethernet ports disabled before configuring
the smart link group.
Configuration Task List
Complete the following tasks to configure Smart Link:
Eth1/0/12
Switch D
Eth1/0/1
Eth1/0/2
BLOCK
Switch B
1-2, Ethernet 1/0/1 on Switch A is active and Ethernet 1/0/2 on Switch A is blocked.
1-3