Configuring Smart Link - 3Com 7757 Configuration Manual

Configuring Smart
Link
Configuration Tasks
Configuring a Smart Link
Device
As shown in Figure 257, Ethernet2/0/1 on Switch A is active and Ethernet2/0/2 on
Switch A is blocked. When the link connected to Ethernet2/0/1 fails, Ethernet2/0/1
is blocked automatically, and the state of Ethernet2/0/2 turns to active state.
When link switching occurs in the Smart Link group, MAC forwarding entries
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and ARP entries of each device in the network may be out of date.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
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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.
n
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.
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After completing the configuration, you need to enable the Ethernet ports
disabled before configuring the Smart Link group.
Table 714 Smart Link configuration tasks
Task
"Configuring a Smart Link Device" on
page 925
"Configuring Associated Devices" on
page 926
A Smart Link device refers to a device on which Smart Link is enabled and a Smart
Link group is configured, and that sends flush messages from the specified control
VLAN. A member port of a Smart Link group can be either an Ethernet port or a
manually-configured or static LACP aggregation group. You can configure a port
or a link aggregation group as a member of a Smart Link group.

Configuring Smart Link

Remarks
Create a Smart Link Required
group
Add member ports to
the Smart Link group
Enable the function of
sending flush messages
in the specified control
VLAN
Enable the function of Required
processing flush
messages received from
the specified control
VLAN
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