Cisco IOS Port Mirroring

How to monitor network traffic through Cisco IOS switches

Configure Catalyst IOS 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> source interface <interface>


monitor session 1 source interface gigabitethernet5/1
  1. Configure the destination port to send the data to

    monitor session <session> destination interface <interface>


monitor session 1 destination interface gigabitethernet5/48
  1. Exit back to configuration mode


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