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    SNMP across VLANs, responses not getting through firewall.

    Scheduled Pinned Locked Moved Firewalling
    20 Posts 3 Posters 1.7k Views
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    • DerelictD
      Derelict LAYER 8 Netgate
      last edited by

      You probably want to packet capture for the SNMP traffic to see where it is going wrong.

      Chattanooga, Tennessee, USA
      A comprehensive network diagram is worth 10,000 words and 15 conference calls.
      DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
      Do Not Chat For Help! NO_WAN_EGRESS(TM)

      1 Reply Last reply Reply Quote 0
      • DerelictD
        Derelict LAYER 8 Netgate @erasedhammer
        last edited by

        @erasedhammer Note your rule has 0 counters which mean it has never received a match since the filter was reloaded. Is there another rule above it that might be matching and policy routing the traffic or something like that?

        Chattanooga, Tennessee, USA
        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
        Do Not Chat For Help! NO_WAN_EGRESS(TM)

        E 1 Reply Last reply Reply Quote 0
        • E
          erasedhammer
          last edited by

          From the same subnet snmp works:
          samesubnet.PNG

          From pfsense (vlan130 interface):
          differentsubnet.PNG

          From pfsense (vlan100 interface):
          diffsubnet2.PNG

          It looks like its getting through the firewall. I have no clue why its responding to a device on the same subnet but not another network.
          I guess this is a dlink issue, dang.

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          • E
            erasedhammer @Derelict
            last edited by

            @Derelict

            Previously I had rules for all the different devices. I have consolidated this rule just now into an alias.

            Here is what I am using now, it still doesn't work though:

            rule.PNG

            hosts.PNG

            states.PNG

            DerelictD 1 Reply Last reply Reply Quote 0
            • DerelictD
              Derelict LAYER 8 Netgate @erasedhammer
              last edited by

              @erasedhammer The firewall cannot make the AP respond to the requests it is sending to it.

              Check the AP for anything that restricts SNMP to its local subnet.

              Chattanooga, Tennessee, USA
              A comprehensive network diagram is worth 10,000 words and 15 conference calls.
              DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
              Do Not Chat For Help! NO_WAN_EGRESS(TM)

              E 1 Reply Last reply Reply Quote 0
              • E
                erasedhammer @Derelict
                last edited by

                @Derelict

                Okay. the documentation on it is crap at the best. I'll have to post somewhere.

                NogBadTheBadN 1 Reply Last reply Reply Quote 0
                • NogBadTheBadN
                  NogBadTheBad @erasedhammer
                  last edited by

                  @erasedhammer

                  This maybe ?

                  Screenshot 2020-08-19 at 14.51.35.png

                  Andy

                  1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

                  1 Reply Last reply Reply Quote 0
                  • DerelictD
                    Derelict LAYER 8 Netgate
                    last edited by

                    Looks like it. That documentation seems fairly comprehensive.

                    Chattanooga, Tennessee, USA
                    A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                    DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                    Do Not Chat For Help! NO_WAN_EGRESS(TM)

                    NogBadTheBadN 1 Reply Last reply Reply Quote 0
                    • NogBadTheBadN
                      NogBadTheBad @Derelict
                      last edited by

                      @Derelict said in SNMP across VLANs, responses not getting through firewall.:

                      Looks like it. That documentation seems fairly comprehensive.

                      I did just pick a random D-Link device manual so I could be wrong 😬

                      Andy

                      1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

                      DerelictD E 2 Replies Last reply Reply Quote 0
                      • DerelictD
                        Derelict LAYER 8 Netgate @NogBadTheBad
                        last edited by

                        @NogBadTheBad oh ok lol

                        Chattanooga, Tennessee, USA
                        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                        Do Not Chat For Help! NO_WAN_EGRESS(TM)

                        1 Reply Last reply Reply Quote 0
                        • E
                          erasedhammer @NogBadTheBad
                          last edited by

                          @NogBadTheBad

                          Yeah wrong manual. The device I got said clearly it supports snmpv3, but turns out theres no way to change it and it only supports v2c, but I can live with that.

                          The snmp menu on this wap is very barebones, only fields are enabled, public/private strings, and trap ip. Nothing else.

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                          • E
                            erasedhammer
                            last edited by

                            Problem solved:

                            Ended up being an arp anti spoofing setting binding the default gateway IP to its MAC, but since pfsense is doing the routing the device was blocking another IP (the server) from using that mac.

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