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    Default Deny rule running on an interface with a "pass all" rule

    Scheduled Pinned Locked Moved Firewalling
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    • S
      Stobber
      last edited by

      I have a bridge connecting my WLAN and LAN segments. I'm seeing a lot of blocks in the firewall log, even though that interface has a single rule that allows all traffic through. The blocks all say the "default deny rule" caught them, but why would that get executed at all?

      Big screenshot of everything I think is relevant, with comments in purple text:

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      • S
        Stobber
        last edited by

        Evidently (based on reading the pfSense Book https://portal.pfsense.org/docs/book/firewall/viewing-the-firewall-logs.html#why-do-i-sometimes-see-blocked-log-entries-for-legitimate-connections) this is normal behavior, and it doesn't indicate actually blocked traffic.

        This is likely to happen when a TCP FIN packet, which would normally close the connection, arrives after the connection’s state has been removed…You will see this on occasion even if you have allow all rules on all your interfaces, as allow all for TCP connections only allows TCP SYN packets. All other TCP traffic will either be part of an existing state in the state table, or will be packets with spoofed TCP flags.

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        • johnpozJ
          johnpoz LAYER 8 Global Moderator
          last edited by

          no the packets were blocked.. But yes its normal for out of state.. But you picture doesn't show us flags on the packets so can not see if they are S or A, etc..

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          • S
            Stobber
            last edited by

            @johnpoz:

            no the packets were blocked.. But yes its normal for out of state..

            Right. That's what I said in my second post where I quoted the book.

            @johnpoz:

            But you picture doesn't show us flags on the packets so can not see if they are S or A, etc..

            Yes it does; it just doesn't fit in the CSS frame width on your browser/monitor. There's a scrollbar below the pic…use it to scroll right and you'll see the "Proto" column.

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