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    Another IPv6 weirdness with ISP

    Scheduled Pinned Locked Moved IPv6
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    • G
      gromit1234
      last edited by

      This one is driving me a little crazy, so apologies for the 'another ISP' thread, but I don't know where else to turn.

      I'm with a UK ISP called IDNet who offer a /48 delegated IPv6 range.
      My WAN interface uses DHCPv6 (PPPoE for IPv4) and I've got 'use IPv4 connectivity as parent interface' ticked.
      My LAN is set up to use 'Track Interface' with a suitable Prefix ID set.
      RA is set to 'Assisted'
      ( I'll apologise now for missing anything out!)

      My clients can get an address, they can ping both sides of the router, they can look up IPv6 DNS (pi-hole server, but I've tried other methods). Some sites connect just fine (ipv6.google.com), ifconfig.co will return my clients IPv6 address (Windows 10). So far so good.

      But then there are other sites. If I go to test-ipv6.com, it reports issues. IPv6 tests fail after 15 seconds. One of my mail servers times out. Trying to get to forum.netgate.com times out.

      I've wiped my pfsense (23.05) install and tried again, but with the same results. I believe the firewall to be OK ( a wildcard IPv4 rule and a wildcard IPv6 rule, both on the LAN side) - both have traffic counts which are reasonable.

      I'm not even sure what to try next. I can look up a lot of the failing sites, and even do a TCP connection (to simulate the start of a web connection). I'm beginning to wonder if this is some sort of dual stack issue. But there again, none of this seems to make sense.

      It feels like I've just missed something somewhere...

      Help?!

      JKnottJ johnpozJ GertjanG RobbieTTR 4 Replies Last reply Reply Quote 0
      • JKnottJ
        JKnott @gromit1234
        last edited by

        @gromit1234 said in Another IPv6 weirdness with ISP:

        If I go to test-ipv6.com

        What issues?

        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...

        G 1 Reply Last reply Reply Quote 0
        • G
          gromit1234 @JKnott
          last edited by

          @JKnott said in Another IPv6 weirdness with ISP:

          What issues?

          I knew I'd miss something.
          IPv4 tests are OK. Any other test will time out after 15 seconds.
          Opening one of the idividual tests in it's own tab will time out.

          JKnottJ 1 Reply Last reply Reply Quote 0
          • JKnottJ
            JKnott @gromit1234
            last edited by

            @gromit1234

            Sounds like you don't have IPv6. When you go to ipv6.google.com, are you able to do anything?

            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...

            G 1 Reply Last reply Reply Quote 0
            • johnpozJ
              johnpoz LAYER 8 Global Moderator @gromit1234
              last edited by

              @gromit1234 said in Another IPv6 weirdness with ISP:

              they can look up IPv6 DNS (pi-hole server

              via GUA or some link local address? You can look up a IPv6 address ie AAAA over IPv4..

              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
              • GertjanG
                Gertjan @gromit1234
                last edited by

                @gromit1234 said in Another IPv6 weirdness with ISP:

                If I go to test-ipv6.com, it reports issues

                Ok, you didn't saw this one :

                049cbd7c-9e00-4114-8bf0-a7e9fafd5233-image.png

                What you want to see and share is this one :

                e71fada9-1682-40d4-80a9-4eaaa155e0ef-image.png

                No "help me" PM's please. Use the forum, the community will thank you.
                Edit : and where are the logs ??

                G 1 Reply Last reply Reply Quote 0
                • RobbieTTR
                  RobbieTT @gromit1234
                  last edited by RobbieTT

                  @gromit1234 said in Another IPv6 weirdness with ISP:

                  Help?!

                  Help offered - I'm also with iDNet (good idea going with a quality ISP over a cheap one) so can offer any settings you need. ๐Ÿ‘

                   2023-06-15 at 14.42.43.png

                   2023-06-15 at 14.50.37.png

                  โ˜•๏ธ

                  1 Reply Last reply Reply Quote 0
                  • RobbieTTR
                    RobbieTT
                    last edited by RobbieTT

                    The physical WAN link (to my ONT) - Don't miss the 1508 MTU setting for PPPoE overhead:

                     2023-06-15 at 14.55.34.png

                    Main LAN configuration:

                     2023-06-15 at 14.56.07.png

                    Hope these help - if not just ask.

                    โ˜•๏ธ

                    G 1 Reply Last reply Reply Quote 2
                    • G
                      gromit1234 @Gertjan
                      last edited by

                      @Gertjan You're right - I'd love to see those!
                      This is what I get:
                      2023-06-15 19_52_31-Test your IPv6. โ€” Mozilla Firefox.png 2023-06-15 19_52_43-Test your IPv6. โ€” Mozilla Firefox.png 2023-06-15 19_52_56-Test your IPv6. โ€” Mozilla Firefox.png

                      If I I try one of the URLs which times out (e.g. the vm3 link) as an individual page, it still times out:
                      2023-06-15 19_53_45-Problem loading page โ€” Mozilla Firefox.png

                      If I try a test-netconnection on port 443, it's OK:
                      2023-06-15 19_54_21-Administrator_ Windows PowerShell.png

                      1 Reply Last reply Reply Quote 0
                      • G
                        gromit1234 @JKnott
                        last edited by

                        @JKnott I get the usual Google page with ipv6.google.com. If I ask it what my IP is, it responds:
                        2023-06-15 19_50_19-what is my IP address - Google Search โ€” Mozilla Firefox.png

                        If I go to ifconfig.co, it tells me the same:
                        2023-06-15 19_49_50-What is my IP address_ โ€” ifconfig.co โ€” Mozilla Firefox.png

                        1 Reply Last reply Reply Quote 0
                        • G
                          gromit1234 @RobbieTT
                          last edited by

                          @RobbieTT
                          OMG - it was in there!
                          You're using FTTP (I think), but your point about MTU got me thinking....
                          The WAN was set to 1492 by the ISP. The LAN defaulted to 1500. I changed this to 1492 et voila!

                          THANK YOU SO MUCH!

                          @JKnott @johnpoz @Gertjan Thank you for jumping in and helping. It was the MTU size which was killing packets... I finally got there!
                          success.png

                          RobbieTTR 1 Reply Last reply Reply Quote 0
                          • RobbieTTR
                            RobbieTT @gromit1234
                            last edited by

                            @gromit1234 said in Another IPv6 weirdness with ISP:

                            @RobbieTT
                            OMG - it was in there!
                            You're using FTTP (I think), but your point about MTU got me thinking....
                            The WAN was set to 1492 by the ISP. The LAN defaulted to 1500. I changed this to 1492 et voila!

                            THANK YOU SO MUCH!

                            ๐Ÿ‘

                            No problem at all. It does not matter if you are on FTTP or not, the physical link on the WAN to your ADSL/VDSL2/G.fast modem should be 1508 MTU, allowing a normal 1500 MTU to traverse wearing the 8-byte PPPoE wrapper (ie as per my settings).

                            โ˜•๏ธ

                            1 Reply Last reply Reply Quote 1
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