Posts Tagged ‘Switch’

How to configure a switch port to work in Promiscuous mode?

Following are the steps to configure a switch port to work in promiscuous mode.

  1. Connect to console port (using hyper terminal [port com1, speed 9600 bps]).
  2. Run the following commands:

    # configure terminal.

    # no monitor session 1.

    # monitor session 1 source interface fastEthernet 0/1.

    # monitor session 1 destination interface fastEthernet 0/24.

    # encapsulation dot1q.

    # end

    # show monitor session1.


    [Note: Promiscuous mode refers to the special mode of Ethernet hardware, in particular network interface cards (NICs), that allows a NIC to receive all traffic to the network, even if it is not addressed to this NIC. In a wider sense, promiscuous mode also refers to network visibility from a single observation point.]