H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 625)

61-2
How Monitor Link Works
Figure 61-2 Network diagram for a Monitor Link group implementation
BLOCK
Switch A Switch B
GE1/0 /1
GE1 /0/2
Switch C Switch D
Switch E
GE1 /0/1
GE1 /0/2
GE1/0 /3
GE 1/0/1
GE 1/0/2
GE1/0/3
GE 1/0/11 GE1/0/12
As shown in Figure 61-2 , 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 GigabitEthernet 1/0/1 is the uplink port, while
GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 are the downlink ports. Switch A is configured with a
Smart Link group, where GigabitEthernet 1/0/1 is the master port and GigabitEthernet 1/0/2 is the slave
port.
z
If Switch C is not configured with Monitor Link group, when the link for the uplink port
GigabitEthernet 1/0/1 on Switch C fails, the links in the Smart Link group are not switched because
the link for the master port GigabitEthernet 1/0/1 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 GigabitEthernet 1/0/1.
z
If Switch C is configured with Monitor Link group and Monitor Link group detects that the link for the
uplink port GigabitEthernet 1/0/1 fails, all the downlink ports in the group are shut down; therefore,
GigabitEthernet 1/0/3 on Switch C is blocked. Now, Smart Link group configured on Switch A
detects that a link fault occurs on the master port GigabitEthernet 1/0/1. Then, Smart Link
immediately activates the slave port GigabitEthernet 1/0/2 so that traffic is switched to the backup
link.
z
Currently, member ports of a Monitor Link group cannot be dynamic link aggregation groups.
z
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.