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    Cannot block incoming ping responses

    Scheduled Pinned Locked Moved Firewalling
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    • E
      einar
      last edited by

      Coming from iptables, setting up ping behavior is more complicated. So, I was surprised that by blocking ping requests on WAN to ANY incoming pings are out. Yet, LAN can ping outside and receive a reply. Perfect.

      For testing, I wanted to block ping responses on WAN to lan address. This should also "stop" LAN pings to the outside (because the response cannot come back to LAN). However, it does not.

      Any idea why?

      I switched off "Block private networks" and "Block bogus networks" to be able to test on a private network.

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        If you don't want your lan to ping stuff outside pfsense, then create a lan rule to block ICMP from going out in the first place.

        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 2.8, 24.11

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        • E
          einar
          last edited by

          To reach the goal (as in "use case"), I totally agree. However, the firewall should be able to block incoming ping replies. And somehow, I am unable to set this up.

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by

            If you allow icmp out, then your allowing the state to be created - now you want a rule to deny the return traffic to the state..  That is not the logical way to go about what your wanting to do.

            The logical way to accomplish your goal is to never allow outbound in the first place to things you don't want your clients to do.

            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 2.8, 24.11

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