2-2How Monitor Link WorksFigure 2-2 Network diagram for a Monitor Link group implementationBLOCKSwitch A Switch BGE 1/0 /1 GE1 /0/2Switch C Switch DSwitch EGE1 /0/1GE1 /0/2GE 1/0 /3GE 1/0/1GE 1/0/2 GE1/0/3GE 1/0/11 GE1/0/12As shown in Figure 2-2, 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, whileGigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 are the downlink ports. Switch A is configured with aSmart Link group, where GigabitEthernet 1/0/1 is the master port and GigabitEthernet 1/0/2 is the slaveport.z If Switch C is not configured with Monitor Link group, when the link for the uplink portGigabitEthernet 1/0/1 on Switch C fails, the links in the Smart Link group are not switched becausethe link for the master port GigabitEthernet 1/0/1 of Switch A configured with Smart Link groupoperates normally. Actually, however, the traffic on Switch A cannot be up-linked to Switch Ethrough 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 theuplink 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 Adetects that a link fault occurs on the master port GigabitEthernet 1/0/1. Then, Smart Linkimmediately activates the slave port GigabitEthernet 1/0/2 so that traffic is switched to the backuplink.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 cannotdirectly delete this aggregation group or change this aggregation group into a dynamic aggregationgroup. To delete this aggregation group, you must first unbind this aggregation group from theMonitor Link.
