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    Forward port opens port to all PCs?

    NAT
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    • M
      MrGlasspoole
      last edited by

      Hi,

      i open a port for uTorrent.
      With commercial routers it was always the case that the port was just
      open on the PC it was forwarded. But now if i make a port check the
      port is also open on another PC.

      What i also don't understand is that uTorrent is not in the Windows firewall
      on the other PC but appears open?

      I made the check with: https://www.grc.com/x/ne.dll?bh0bkyd2
      Firewall-NAT-Port-Forward-Edit.png

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        What do you mean open to all pcs.. You are forwarding to 1 IP 192.168.0.6

        Does not matter what pc you run the grc check from.. It hits your public IP, that is fowarded to this 0.6 IP – so yeah it should show open.

        An intelligent man is sometimes forced to be drunk to spend time with his fools
        If you get confused: Listen to the Music Play
        Please don't Chat/PM me for help, unless mod related
        SG-4860 24.11 | Lab VMs 2.7.2, 24.11

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        • M
          MrGlasspoole
          last edited by

          Ok. So it's normal that the ports are then open on all PCs?

          Whit commercial routers it was always the case that port forwarding
          did only work to one PC. Means if you had the same application on two
          PCs you had to use different ports.

          So if i have a HTTP Server port 80 is open everywhere?

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by

            Again its NOT open on all PC..

            How are you thinking it is???  When you check from grc its only talking to your 1 PUBLIC IP!!!  Which that port then gets forwarded to 1 PC behind the nat.. How do you think its open on all pcs??

            It is not possible to forward the same port to multiple IPs behind a nat.

            An intelligent man is sometimes forced to be drunk to spend time with his fools
            If you get confused: Listen to the Music Play
            Please don't Chat/PM me for help, unless mod related
            SG-4860 24.11 | Lab VMs 2.7.2, 24.11

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            • D
              doktornotor Banned
              last edited by

              Layer 8 issue.

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              • M
                MrGlasspoole
                last edited by

                Ok, i thought this port checkers check only on the PC you run them.

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                • KOMK
                  KOM
                  last edited by

                  It's going to check your public presence only.  It can't easily tell if you're behind some NAT devices.  So even though you're running a port scan from your PC behind the firewall, the scan is really targeting the firewall and not your PC.

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