Cisco Catalyst Port Mirroring

How to monitor network traffic through Cisco Catalyst switches

Configure Catalyst Switch

  1. Open a session on the switch

  2. Enter configure mode

    configure terminal

  3. Check for existing monitor sessions

    show monitor session

  4. Set the interface to monitor

    monitor session <session number> source interface <interface>


monitor session 1 source interface gigabitethernet0/0/1
5. Configure the destination port to send the data to

monitor session <session number> destination interface <interface> encapsulation replicate


monitor session 1 destination interface gigabitethernet0/0/2 encapsulation replicate
  1. Exit back to configuration mode


Once you have verified that your configuration is correct, make sure to save it.