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    Active IPsec tunnel between pfSense and OPNsense is active, suddenly reconnects with 0 bytes in phase 2

    Scheduled Pinned Locked Moved General pfSense Questions
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    • C
      cwo @stephenw10
      last edited by

      @stephenw10

      Hi. Yes, there is no traffic on both sides. I try to do some screenshots on Monday.

      Regards,
      Christian

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      • stephenw10S
        stephenw10 Netgate Administrator
        last edited by

        Even when initiated from either side?

        If one side was doing something odd I might expect to at least see outbound packets on one side if traffic was initiated from that side.

        If there's actually no traffic at all it sounds like maybe the routes are missing so it's not trying.

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        • C
          cwo @stephenw10
          last edited by

          @stephenw10

          Sorry for the delay. The connection is initiated from pfSense (branch office)to OPN (hq). The OPN is only waiting for incoming requests. We use a certificate based authentication, not PSK.

          Yesterday, I found the IPsec tunnel in this state:
          20231113-0842.png

          On the other side, I found that SPIs of "Phase 2" does not match on both sides:

          20231113-0844.png

          After dropping the tunnel (restarting the service) on the pfSense side, it went back online but traffic flows only in one direction:

          20231113-0846.png

          Then I did the same thing I do every day when this happens: I went on the OPN-side in the Phase 1, did a very small changed within the DPD (for example change the delay from default 10 seconds to 9 seconds) just to make a change and get the ability to "apply" the changes.

          This seams to reset something and the traffic immediately starts running through the tunnel.

          I will try to provide a pfSense ipsec-log but the log contain a lot of personalized information like IP addresses, certificate names of my company ... that needs to be truncated first.

          Regards,

          Christian

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          • C
            cwo @michmoor
            last edited by

            @michmoor

            Sorry for the delay. I attached the ipsec.log file from the pfSense.

            ipsec.txt

            Regards,
            Christian

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            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              Nothing logged there really looks like a significant error.

              In any of those intermediate states do the SPIs match?

              Do you see routes at either end in any of those states?

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              • jimpJ
                jimp Rebel Alliance Developer Netgate
                last edited by

                Any time I've seen issues close to this it's because of collisions in the negotiation where both sides are rebuilding things at the same time and then can end up confused or broken in various ways.

                I'm not sure what options you may have on the peer, but go over all the suggestions here in this doc:

                https://docs.netgate.com/pfsense/en/latest/troubleshooting/ipsec-duplicate-sa.html

                Remember: Upvote with the 👍 button for any user/post you find to be helpful, informative, or deserving of recognition!

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                • C
                  cwo @jimp
                  last edited by

                  @jimp
                  Thank you. This could explain it. I will follow the link and check the options :-)

                  Regards, Christian

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                  • C
                    cwo @stephenw10
                    last edited by

                    @stephenw10

                    When I see this correctly, the SPNs does not match fully.

                    I always thought, that if the tunnel is up, DPD would handle the problem, if SPNs doesn't match?!? It is active on both sides.

                    I don't understand what you are meaning with "seeing routes"? I use a vti mode with static routes defined under System > Gateway. Looking at the tunnel status under

                    Status > IPsec

                    shows a "Local 0.0.0.0/0" and "Remote 0.0.0.0/0".

                    The gateway, defined within the Netgate, points to the Tunnel-IP from the OPN and vice versa. A route on each side points to the IP network on the other side.

                    I also disabled "Gateway Monitoring" and "Gateway Action".

                    Regards, Christian

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                    • stephenw10S
                      stephenw10 Netgate Administrator
                      last edited by

                      DPD can still work even if the childSAs are mismatched so traffic doesn't actually pass.

                      Do you actually see routes present in the routing tables when it stops passing though? This feels like it could be missing routes that are replaced when you make any save to the tunnel.

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                      • C
                        cwo @stephenw10
                        last edited by

                        @stephenw10

                        Hi Stephen.

                        I give you a reply on this tomorrow (when the error happened again ;-))

                        Regards,
                        Christian

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