Monitoring a Port

To configure port monitoring on an individual port on a device, complete the following steps.
  1. Enter global configuration mode.
    device# configure terminal
  2. Enter the mirror-port command, specifying an interface, to configure the mirror port that functions as the destination port to which the packets that need to be monitored are copied and forwarded. 
    device(config)# mirror-port ethernet 1/2/4
  3. Enter interface configuration mode to configure port monitoring.
    device(config)# interface ethernet 1/2/11
  4. Configure port monitoring to send the traffic from the monitored port to the specified mirror port. 
    device(config-if-e1000-1/2/11)# monitor ethernet 1/2/4 both
Parent topic: Commands for Port Mirroring and Monitoring