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    Site-to-Site OpenVPN Connectivity Problem

    Scheduled Pinned Locked Moved OpenVPN
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    • DerelictD
      Derelict LAYER 8 Netgate
      last edited by

      Yeah. The assigned interfaces are probably unnecessary but having a tunnel network larger than /30 puts an SSL/TLS server into server mode (PtMP) and you would need to add a CSO for the remote networks even if there is only one client.

      Simply changing that tunnel network to /30 kick the server into PtP will relieve you of that burden which is likely overkill on a true PtP connection.

      Also, in SSL/TLS mode you shouldn't need to specify a tunnel or remote networks on the client. Those should be pushed from the server. This allows a more centralized configuration.

      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)

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      • J
        JamesVA
        last edited by

        Thanks for all the replies. I did both - the assignment and the tunnel set to /30 on both sites. Still no-go on the ping from one client to the other.

        However I am seeing a lot more ICMP activity on the packet capture now, even when no client pings are running....is that normal?

        Site A
        16:57:53.190902 IP 172.16.0.1 > 172.16.0.2: ICMP echo request, id 60436, seq 879, length 8
        16:57:53.243548 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 808, length 8
        16:57:53.243586 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 808, length 8
        16:57:53.719702 IP 172.16.0.1 > 172.16.0.2: ICMP echo request, id 60436, seq 880, length 8
        16:57:53.775623 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 809, length 8
        16:57:53.775641 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 809, length 8
        16:57:54.250884 IP 172.16.0.1 > 172.16.0.2: ICMP echo request, id 60436, seq 881, length 8

        Site B
        16:54:32.183967 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 428, length 8
        16:54:32.716163 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 429, length 8
        16:54:33.248410 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 430, length 8
        16:54:33.780685 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 431, length 8
        16:54:34.312925 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 432, length 8
        16:54:34.845193 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 433, length 8
        16:54:35.376665 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 434, length 8
        16:54:35.908906 IP 172.16.0.6 > 172.16.0.5: ICMP echo request, id 19740, seq 435, length 8

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        • J
          JamesVA
          last edited by

          I've also added IPv4 Any/any/any rules to the OVPNS2S interfaces on each side (that's the names i've assigned to them).

          Still no replies from pings.

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          • DerelictD
            Derelict LAYER 8 Netgate
            last edited by

            Those look like gateway monitoring. you can disable that if you don't want it. Else filter on the source or target host IP address so you don't have to look at them.

            Are you sure the far side will respond to pings from a remote subnet? Windows firewall?

            Start at the source. pcap on the lan receiving the echo request. Then pcap on the OpenVPN on that side. Then pcap at the openvpn on the far side. Then the LAN on the far side. If the pings are going through but there is no response there, check the target host. Else see where the replies die.

            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)

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            • J
              JamesVA
              last edited by

              Yup, you're right - those echos were gateway monitoring agents; they're off on both sides for now. To answer your questions:

              Yes, i'm sure the far side should respond. Windows firewall is off and I can ping it from pfsenseB>clientB.

              Start at the source - here are the results. I kind of did those before because other posts suggested that as a form of troubleshooting, but now i did it more thorough....here are the findings:

              pfsenseA > clientA = success
              pfsenseB > clientB = success
              pfsenseA > clientB = fail
              pfsenseB > clientA = fail

              I can try pinging some other-side gateway IPs from each pfsenseX, but i'm not sure which ones to ping. From other forum posts I also gathered that some shouldn't even reply so I don't want to add to confusion by including that in the above tests.

              So so far it still looks like there is no connectivity between the two sides. I also checked the firewall logs and I don't see any rejections that jump out, i.e on ovnpns2(A) or ocpnc1(B) interfaces....

              Appreciate your help. Anything else I can try, or should i be pcap'ing with different switches?

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              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by

                No. You need to packet capture the pings at progressive hop points, not report success or failure of the pings.

                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)

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                • J
                  JamesVA
                  last edited by

                  Ok, gotcha. Then the results are the same. I can't see any pings crossing the tunnel. I see them on each sides pfsense, but they don't come out on the other end.

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                  • DerelictD
                    Derelict LAYER 8 Netgate
                    last edited by

                    That is not enough information to provide any help.

                    Post a pcap of something like a ping -c3 dest at each hop, detailing exactly where each pcap is taken.

                    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)

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                    • J
                      JamesVA
                      last edited by

                      Sorry for the delay in my response - was out of office. Please let me know if you need more info, or if i misunderstood anything.

                      clientA > pfsenseB (ping -c 1 10.0.105.51)

                      clientA:

                      C:\WINDOWS\system32>ping -c 1 10.0.105.1

                      Pinging 10.0.105.1 with 32 bytes of data:
                      Request timed out.
                      Request timed out.
                      Request timed out.
                      Request timed out.

                      Ping statistics for 10.0.105.1:
                      Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

                      C:\WINDOWS\system32>

                      pfsenseA:
                      tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
                      listening on ovpns2, link-type NULL (BSD loopback), capture size 262144 bytes
                      14:17:33.076313 IP 10.0.100.121 > 10.0.105.1: ICMP echo request, id 1, seq 779, length 40
                      14:17:37.670815 IP 10.0.100.121 > 10.0.105.1: ICMP echo request, id 1, seq 780, length 40
                      14:17:42.681825 IP 10.0.100.121 > 10.0.105.1: ICMP echo request, id 1, seq 781, length 40
                      14:17:47.687779 IP 10.0.100.121 > 10.0.105.1: ICMP echo request, id 1, seq 782, length 40

                      pfsenseB:
                      tcpdump is empty

                      clientA > clientB (ping -c 1 10.0.105.51)

                      ClientA:
                      C:\WINDOWS\system32>ping -c 1 10.0.105.51

                      Pinging 10.0.105.51 with 32 bytes of data:
                      Request timed out.
                      Request timed out.
                      Request timed out.
                      Request timed out.

                      Ping statistics for 10.0.105.51:
                      Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

                      C:\WINDOWS\system32>

                      pfsenseA:
                      tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
                      listening on ovpns2, link-type NULL (BSD loopback), capture size 262144 bytes
                      14:21:43.005849 IP 10.0.100.121 > 10.0.105.51: ICMP echo request, id 1, seq 787, length 40
                      14:21:47.666048 IP 10.0.100.121 > 10.0.105.51: ICMP echo request, id 1, seq 788, length 40
                      14:21:52.670818 IP 10.0.100.121 > 10.0.105.51: ICMP echo request, id 1, seq 789, length 40
                      14:21:57.685270 IP 10.0.100.121 > 10.0.105.51: ICMP echo request, id 1, seq 790, length 40

                      pfsenseB:
                      tcpdump is empty.

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                      • DerelictD
                        Derelict LAYER 8 Netgate
                        last edited by

                        @jamesva said in Site-to-Site OpenVPN Connectivity Problem:

                        pfsenseB:
                        tcpdump is empty.

                        Listening where?

                        Sorry. You don't need the -c 1 flag. I forget sometimes that some people still use Windows.

                        Don't need any more ping results. We know it isn't working.

                        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)

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                        • J
                          JamesVA
                          last edited by

                          pfsenseB is the other side psfsense console.

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                          • DerelictD
                            Derelict LAYER 8 Netgate
                            last edited by Derelict

                            Right but capturing on what interface? Need specifics here.

                            And can you ping the pfSense LAN interface address on the other side?

                            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)

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                            • J
                              JamesVA
                              last edited by

                              The captures are running on the ovpn interfaces. Should i have been capturing on another interface?

                              As far as ping LAN interface - no, i can't reach it from one side to another. However if the client is on the same side, pfsense's LAN int responds to pings just fine.

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                              • J
                                JamesVA
                                last edited by JamesVA

                                Having said that, it looks like I can ping clients on Side A if i'm sitting on the console of pfsenseB.....

                                however it doesn't work the opposite way, i.e. if i'm on the console of pfsenseA, i can't reach anything on side B.

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                                • DerelictD
                                  Derelict LAYER 8 Netgate
                                  last edited by

                                  It doesn't make any sense that you are seeing traffic exit the VPN at A but it does not arrive in a capture on openvpn at B.

                                  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)

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                                  • J
                                    JamesVA
                                    last edited by

                                    Could it have something to do with the fact that pfsenseB WAN IP is on 10.x.x.x subnet?

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                                    • DerelictD
                                      Derelict LAYER 8 Netgate
                                      last edited by

                                      Not unless it's within or conflicting somehow eith the others. And you'd still see the packets in the capture on the OpenVPN.

                                      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)

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                                      • J
                                        JamesVA
                                        last edited by

                                        hmm ok, what else can you suggest I try? I do have multiple ovpn instances on SideA, but i can't imagine that would conflict with any of them since they're running on different ports....

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                                        • DerelictD
                                          Derelict LAYER 8 Netgate
                                          last edited by

                                          It's not about ports but addresses/networks. They all need to be unique.

                                          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)

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                                          • J
                                            JamesVA
                                            last edited by

                                            they are; screenshot below.

                                            0_1539288653531_2018-10-11_15-09-37.jpg

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