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    Suricata Alert show ports other than forwarded port, interface DMZ

    Scheduled Pinned Locked Moved IDS/IPS
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    • C
      ccieneverbe
      last edited by ccieneverbe

      Hi All how's going?

      Setting:

      • NAT port forward WAN 6881 to DMZ 6881 , 1 port only
      • Suricata applied on interface DMZ

      Question:
      A) Suricata alert page shows ports other than 6881, is this normal?

      My conjecture is above normal, since IDS/IPS happens before NAT FW.
      Hoping to get confirmation here (Certainly hope not configured NAT FW wrong, poor DMZ server getting hit every port unprotected).

      Question:
      B) The part I don't understand is HOW port !6881 get associated to 192.168.21.2

      Thanks for your time in advance.

      Suricata applied on DMZ
      interface.png

      Suricata alert page shows
      Alert.png

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      • bmeeksB
        bmeeks
        last edited by bmeeks

        The IDS packages sit out in front of the pfSense firewall engine. So they see traffic before any firewall rules or NAT is applied. For Legacy Mode Blocking operation, the IDS engine is getting copies of packets as they traverse from the NIC to the firewall engine in the kernel. For Inline IPS Mode operation, the IDS sits between the NIC and the firewall engine by way of a netmap kernel device network pipe. See the two diagrams below that show the traffic flow for both Legacy Mode Blocking and Inline IPS Mode blocking.

        ids-ips-network-flow-legacy-mode.png

        ids-ips-network-flow-ips-mode.png

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