Configuring Monitor Link - 3Com 7757 Configuration Manual

932 C 85: M
HAPTER ONITOR
How Monitor Link
Works
Configuring Monitor
Link
L C
INK ONFIGURATION
Figure 260 Network diagram for a Monitor Link group implementation
Eth 2 / 0/ 11
Switch C
Eth 2/ 0 / 1
Eth 2/ 0 / 2
Eth 2/ 0 / 3
Eth 2/ 0 / 1
Eth 2/0 / 2
Switch A
As shown in Figure 260, the devices Switch C and Switch D are connected to the
uplink device Switch E. Switch C is configured with a Monitor Link group, where
Ethernet2/0/1 is the uplink port, while Ethernet2/0/2 and Ethernet2/0/3 are the
downlink ports. Switch A is configured with a Smart Link group, where
Ethernet2/0/1 is the master port and Ethernet2/0/2 is the slave port.
If Switch C is not configured with Monitor Link group, when the link for the
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uplink port Ethernet2/0/1 on Switch C fails, the links in the Smart Link group
are not switched because the link for the master port Ethernet2/0/1 of Switch
A configured with Smart Link group operates normally. Actually, however, the
traffic on Switch A cannot be up-linked to Switch E through the link of
Ethernet2/0/1.
If Switch C is configured with Monitor Link group and Monitor Link group
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detects that the link for the uplink port Ethernet2/0/1 fails, all the downlink
ports in the group are shut down; therefore, Ethernet2/0/3 on Switch C is
blocked. Now, Smart Link group configured on Switch A detects that a link
fault occurs on the master port Ethernet2/0/1. Then, Smart Link immediately
activates the slave port Ethernet2/0/2 so that traffic is switched to the backup
link.
n
Currently, member ports of a Monitor Link group cannot be dynamic link
■
aggregation groups.
If the uplink or downlink port in the Monitor Link group is a link aggregation
■
group, you cannot directly delete this aggregation group or change this
aggregation group into a dynamic aggregation group. To delete this
aggregation group, you must first unbind this aggregation group from the
Monitor Link.
n
Before configuring a Monitor Link group, you must create a Monitor Link group
and configure member ports for it. A Monitor Link group consists of an uplink port
Eth 2 / 0 / 12
Switch E
Switch D
Eth 2 / 0 / 1
Eth 1 / 0 / 2
BLOCK
Switch B