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    OpenVPN and Deutsche Glasfaser - IPV6 and CGNAT blocking connection?

    Scheduled Pinned Locked Moved OpenVPN
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    • JKnottJ
      JKnott @netblues
      last edited by

      @netblues

      The WAN address may often have a host name which can be used. Use host or nslookup command on the WAN address to see what turns up.

      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...

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      • JKnottJ
        JKnott @charry2014
        last edited by

        @charry2014 said in OpenVPN and Deutsche Glasfaser - IPV6 and CGNAT blocking connection?:

        6rd Prefix: 2A00:61E0::

        They're using a tunnel, rather than native IPv6. I used a tunnel for the first 6 years I had IPv6, but now I get a native IPv6 connection from my ISP. I'm surprised they're using a tunnel and CGNAT. How old is that info? My ISP also used a tunnel (though not the one I used) prior to providing native IPv6. If they're using a tunnel these days, I'd have to question their competence.

        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...

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        • Bob.DigB
          Bob.Dig LAYER 8
          last edited by Bob.Dig

          Does your (smartphone) service provider has IPv6? Than you can connect OVPN via IPv6 directly.

          Bob.DigB 1 Reply Last reply Reply Quote 0
          • C
            charry2014
            last edited by

            I could get my IPv6 address from https://ipv6-test.com/ easily enough but have drawn a blank trying to test OpenVPN connecting to it. Both running the OpenVPN client on my phone, and using the phone as wifi hotspot for my Mac result in no packets received at the PFSense WAN. Tunnelblick on Mac reports:
            2020-07-26 15:43:16.288025 write UDPv6: No route to host (code=65)

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            • Bob.DigB
              Bob.Dig LAYER 8 @Bob.Dig
              last edited by Bob.Dig

              Please answer the question:

              @Bob-Dig said in OpenVPN and Deutsche Glasfaser - IPV6 and CGNAT blocking connection?:

              Does your (smartphone) service provider has IPv6?

              1 Reply Last reply Reply Quote 0
              • C
                charry2014
                last edited by charry2014

                Yes. My phone (Samsung S20) is on Vodafone in Germany and I have read that they have IPv6 nationwide.
                Edit - I did some digging and it has an IPv6 address too.

                Bob.DigB 1 Reply Last reply Reply Quote 0
                • Bob.DigB
                  Bob.Dig LAYER 8 @charry2014
                  last edited by

                  @charry2014 That's great, you don't need any IPv4, at least not if you want to connect the phone to home via OVPN.

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                  • C
                    charry2014
                    last edited by

                    The site https://ipv6-test.com/ reports that my firewall is filtering ICMP v6 messages. Could this be a problem for OpenVPN? I am suspecting it might. How do I enable this?

                    JKnottJ 1 Reply Last reply Reply Quote 0
                    • Bob.DigB
                      Bob.Dig LAYER 8
                      last edited by Bob.Dig

                      No. How is your IPv6 configured? I think your ISP is doing native IPv6.

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                      • C
                        charry2014
                        last edited by

                        I think so too, but I am not sure of much from my ISP.

                        One thing I did notice is that when I connect to whatismyipaddress.com or similar from different computers in my LAN that the IPv6 address that is returned is different for each one. The IPv4 address is the same, as I would expect. Now I think I am stumbling into a noob difference between IPv4 and IPv6 addresses.

                        So the question - what actually is the IPv6 address of my PFSense WAN?

                        JKnottJ 1 Reply Last reply Reply Quote 0
                        • Bob.DigB
                          Bob.Dig LAYER 8
                          last edited by Bob.Dig

                          You can see it in the interfaces-gadget and other places. 😉 (Status - Interfaces)

                          1 Reply Last reply Reply Quote 0
                          • C
                            charry2014
                            last edited by

                            Alright - so it is something like 2a00:61e0:abcd🔢:?

                            It is not the much longer address 2a00:61e0:b00b5:34dd:6969:beef:babe:face?

                            Bob.DigB 1 Reply Last reply Reply Quote 0
                            • Bob.DigB
                              Bob.Dig LAYER 8 @charry2014
                              last edited by Bob.Dig

                              @charry2014 Can't say but maybe you did something wrong. Try this and go for DHCPv6 and not 6rd.

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                              • C
                                charry2014
                                last edited by

                                Boom - that did it - using the IPv6 address for the WAN as shown in the Interfaces widget on the dashboard packets are now flowing.

                                I now get an authentication error, but the connection is there. Authentication errors are kinda the staple for getting OpenVPN working so somehow I am back on known territory now.

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                                • JKnottJ
                                  JKnott @charry2014
                                  last edited by

                                  @charry2014

                                  No, OpenVPN uses UDP, not ICMPv6. However, ICMPv6 is used for a lot of things, so be careful about any rules blocking it.

                                  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...

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                                  • JKnottJ
                                    JKnott @charry2014
                                    last edited by

                                    @charry2014

                                    One nice thing about IPv6 is there are plenty of addresses to go around. This means no longer having to share an address with NAT. Not only does each device get an address, it will often get several. With SLAAC, privacy addresses are often used. These are random number based addresses and you get a new one every day. They expire after a week. This is in addition to the consistent address, so you could have as many as 8 public addresses on each device.

                                    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
                                    • C
                                      charry2014
                                      last edited by

                                      Thanks everyone for your help - it seems that a little background reading would be a good idea sometime soon. This may well change the settings in the firewall rules, then?

                                      JKnottJ 1 Reply Last reply Reply Quote 0
                                      • JKnottJ
                                        JKnott @charry2014
                                        last edited by

                                        @charry2014

                                        That depends on what the rules do. If filtering on protocol, then you can often create a single rule that handles both. If filtering on address, then you'd need separate rules.

                                        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
                                        • C
                                          charry2014
                                          last edited by

                                          So here it is, best I can remember it. All the things I changed to get this working:

                                          System - Advanced - Networking
                                          a539b8e1-4fea-4842-a249-397b68fe9769-image.png

                                          Interfaces - WAN
                                          0f469929-d495-4ecc-918c-10c081001e7f-image.png
                                          d5ac4ad4-c53f-4b6c-b78b-d608e71c7687-image.png

                                          Interfaces - LAN:
                                          cb7eb2b6-7155-4731-8e0d-eeae16b2cae9-image.png
                                          6655c340-d9fb-4936-ae80-1b32133c45ef-image.png

                                          The PFSense WAN IPv6 address is then in the Dashboard.

                                          Finally I meant to link to beechy.de above but got the wrong link pasted in.

                                          JKnottJ 1 Reply Last reply Reply Quote 0
                                          • JKnottJ
                                            JKnott @charry2014
                                            last edited by

                                            @charry2014

                                            That link @Bob-Dig provided says 6rd is going to be shut down, which means you should be configuring for DHCPv6 instead. My ISP did the same thing. They provided both 6rd and 6to4 tunnels, until they provided native IPv6 via DHCPv6-PD. This is what you should be configuring for, as that link describes.

                                            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 1
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