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Help! Cisco Switch port (interface) forwarding

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  • Help! Cisco Switch port (interface) forwarding

    Hi. I am currently designing a test platform for a small company and I want to ask if anybody knows (if it is possible) to forward traffic from one port (physical interface) to another on a Switch. What I am truing to accomplish is to get traffic from one interface (Fa 0/0) and directly forward it to another interface (Fa 0/1).

    In other words....all incoming traffic from port Fa 0/0 of the Switch to be implicitly redirected as outgoing traffic to port Fa 0/1 of the Switch. if not all traffic, maybe it is possible to forward the traffic based on source MAC.

    I am stuck on this problem for a couple of weeks and it seems that there is no solution (to my knowledge). I will be happy to hear your opinion. Thanks!

  • #2
    Re: Help! Cisco Switch port (interface) forwarding

    It is not very clear what are you trying to achieve from what I have read but you can use vlans and you can include only these two ports in one vlan so that other ports will not be burdened by this flow.
    Info on how to configure vlans (nice video from David Davis)
    Last edited by alexbg; 21st March 2010, 11:48.


    • #3
      Re: Help! Cisco Switch port (interface) forwarding

      You are right, I wasn't very clear. The example with the two Fa ports was a simplified version of the whole idea... I need to do that with all 24/48 ports on the switch, and I can't use VLANs because they require different networks. The whole implementation should be in one and the same network/ subnet.

      I tried with route-map,but still, it can be applied only to VLANs (on the Switch) not to actual interfaces. The forwarding criteria should be either incoming IP on the Interface or Incoming MAC of the packet.

      If anybody knows ho to modify the switching table it might help.


      • #4
        Re: Help! Cisco Switch port (interface) forwarding

        OK. Here is what you can do. You can put the vlans as described in my previous post and the hosts on this vlan(e.g. vlan 2, port fa0/1, port fa0/2) which is on this two ports even they are on one subnet with the other host on the switch will not communicate with the hosts on the other vlans (e.g vlan 1, ports fa0/3-0/24) on the other ports.
        However if you want to make the communication possible between the artificially (and some kind wrong in my opinion) separated network(subnet) you will need a router (or better two) and NAT then you can reconnect (actually route) the hosts which were separated before in the switch. Maybe you will need to set different gateways in some cases. It doesn't make sense in doing so but maybe in some situations you need this.
        Last edited by alexbg; 22nd March 2010, 21:43.