Monitoring an individual LAG port

You can monitor the traffic on an individual port of a static LAG group, and on an individual port of an LACP LAG group.

By default, when you monitor the primary port in a LAG group, aggregated traffic for all the ports in the LAG group is copied to the mirror port. You can configure the device to monitor individual ports in a LAG group. You can monitor the primary port or a secondary port individually.

To configure port monitoring on an individual port in a LAG group, enter commands such as the following.

device(config)# lag automation static id 1
device(config-lag-automation)# ports ethernet 1/1/2 to 1/1/9 
device(config-lag-automation)# primary-port 1/1/2
device(config-lag-automation)# deploy
device(config)# mirror-port ethernet 1/1/1 
device(config)# lag automation
device(config-lag-automation)# monitor ethe-port-monitored 1/1/2 ethernet 1/1/1 both

device# show mirror
Mirror port 1/1/1
  Input monitoring      : (U1/M1)   1 
  Output monitoring     : (U1/M1)   1

device# show mirror ethernet 1/1/1
Mirror port 1/1/1
  Input monitoring      : (U1/M1)   1 
  Output monitoring     : (U1/M1)   1

device# show running-config | i mirror
mirror-port ethernet 1/1/1

device# show running-config | i monitor ethernet
monitor ethe-port-monitored 1/1/2 ethe 1/1/1 both

Traffic on LAG port e 1/1/2 is monitored, and the monitored traffic is copied to port e 1/1/1, the mirror port.