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Stop broadcast on non-connected interface

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  • G
    girkers
    last edited by girkers Jul 26, 2020, 3:15 AM Jul 26, 2020, 3:12 AM

    I am "new" to pfsense and need some help.

    pfsense is installed on ESXi v6.5 and I have three (3) NICs attached:

    • VMX0 - WAN

    • VMX1 - LAN

    • VMX2 - vLANS

    What is happening is a computer on the LAN is broadcastings to the LAN Broadcast address x.x.x.255 however it is going out to the vLAN adapter. It makes no difference if the VMX2 is allocated or not, it simple changes the name in the Firewall when you see the block.

    Can I stop this from happening or do I have to suppress the log entry? I would prefer the former.

    Thanks

    J 1 Reply Last reply Jul 26, 2020, 10:49 AM Reply Quote 0
    • J
      JKnott @girkers
      last edited by Jul 26, 2020, 10:49 AM

      @girkers

      What is it broadcasting? You can use Packet Capture to see what.

      PfSense running on Qotom mini PC
      i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
      UniFi AC-Lite access point

      I haven't lost my mind. It's around here...somewhere...

      1 Reply Last reply Reply Quote 0
      • J
        johnpoz LAYER 8 Global Moderator
        last edited by Jul 26, 2020, 10:53 AM

        @girkers said in Stop broadcast on non-connected interface:

        however it is going out to the vLAN adapter.

        No it isn't - you don't have your L2 networks actually isolated if your seeing broadcast traffic on any other than the L2 the device that is broadcasted is connected to..

        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

        1 Reply Last reply Reply Quote 0
        • G
          girkers
          last edited by Jul 27, 2020, 12:06 AM

          There are a number of devices on my network that are doing the broadcast, here is an example:

          Jul 27 09:50:00 vmx2 (1000002620) 192.168.254.174:5353 224.0.0.251:5353 UDP
          Jul 27 09:50:00 vmx2 (1000002620) 192.168.254.174:5353 224.0.0.251:5353 UDP
          ...
          Jul 27 09:56:11 vmx2 (1000002620) 192.168.254.92:61519 192.168.254.255:1947 UDP

          My Interface assignments are:

          Interface Network port
          WAN vmx0
          LAN vmx1
          Media VLAN xx on vmx2
          Camera VLAN xx on vmx2
          Guest VLAN xx on vmx2
          Available network ports: vmx2

          I am confused by this: "you don't have your L2 networks actually isolated if your seeing broadcast traffic on any other than the L2 the device is broadcasted is connected to"

          I do have Avahi installed for mDNS reflexion across my vLANs, but all of the traffic is coming from my LAN onto the vmx2.

          Yes I get the basic difference between a L3 and L2 networks, but that doesn't solve my confusion as to why a Broadcast on my LAN is trying to be "routed" to vmx2 an adapter that is not even connected to a network (in theory). Let alone how to stop if from happening.

          Cheers

          J 1 Reply Last reply Jul 27, 2020, 1:43 AM Reply Quote 0
          • J
            johnpoz LAYER 8 Global Moderator
            last edited by johnpoz Jul 27, 2020, 12:32 AM Jul 27, 2020, 12:24 AM

            You have your L2 connected in your VM then... Broadcast traffic like you posted, will not be routed.. If your seeing broadcast on a different interface than the interface connected to that specific L2, then you have your L2 networks connected somewhere..

            You have to find how your L2 are connected together..

            edit: So this
            Jul 27 09:56:11 vmx2 (1000002620) 192.168.254.92:61519 192.168.254.255:1947 UDP

            Your saying that 192.168.254 is not the network on your vmx2 interface? Your saying that is your LAN network?? What is the networks on your vmx2?

            If your saying that 192.168.254 is not a network on your vmx2 interface, ie if that is your LAN... Then you have them connected somewhere.. There is no possible way for broadcast on your vmx1 network to be seen on your vmx2 interface unless you have those 2 different L2 networks connected somewhere.. Be it a wire, be vswitch not handling tags correctly or something on both your vmx1 network and your vmx2 bridging the traffic..

            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

            G 1 Reply Last reply Jul 27, 2020, 8:50 AM Reply Quote 1
            • J
              JKnott @girkers
              last edited by Jul 27, 2020, 1:43 AM

              @girkers

              Those aren't broadcasts, they're multicasts. That address and port is for mDNS.

              PfSense running on Qotom mini PC
              i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
              UniFi AC-Lite access point

              I haven't lost my mind. It's around here...somewhere...

              1 Reply Last reply Reply Quote 0
              • G
                girkers @johnpoz
                last edited by Jul 27, 2020, 8:50 AM

                @johnpoz

                That now makes sense, I was looking in the wrong spot.

                Looking at the way I have my vSwitch configured I have three (3) NICs that are shared across both my LAN and vLANs and that is where the traffic is getting through.

                Thanks for taking the time to clarifying for me.

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