Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    Prevent IPv6 Address Detection?

    Scheduled Pinned Locked Moved IPv6
    12 Posts 4 Posters 1.9k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • GertjanG
      Gertjan
      last edited by

      http://test-ipv6.com/ and http://ipv6-test.com/ will confirm that your are NOT IPv6 ready  ;)

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

      1 Reply Last reply Reply Quote 0
      • M
        mscaff
        last edited by

        Confirmed not showing an address there at all, but did show IPV6 -> V4 DNS, could that leak in any way?

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

          Sure it wasn't your browser reporting its link-local address?  What was beginning part of this ipv6 address they detected?

          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
          • M
            mscaff
            last edited by

            Can it detect a link-local externally?

            And I'm actually asking for a friend, so I'll need to ask him if the address started with FE80.

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

              could of been a teredo or isatap, etc. – get the first part of the prefix and we can tell if actual global address or some other special sort of address.  And sure browsers can report their IP addresses..  I don't actually recall ever seeing a link local being reported, but browsers can leak all kinds of info.

              https://browserleaks.com/

              browserdetect.png
              browserdetect.png_thumb

              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
              • M
                mscaff
                last edited by

                Ahh I see where you're coming from - fair call, I'll run that by him, pretty sure you're onto it, as I've disabled IPv6 for DHCP and am not leaking.

                I still have a local IPv6 address, from what I've heard you cant disable it, but PFsense just wont use it right?

                Also, curious, can a v6 address leak through a VPN and compromise anonymity?

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

                  you can disable your link local if your on windows for sure.. This will also disable all the other transition tunnel stuff that MS in their infinite wisdom thought was good idea to turn all 3 different ones all at once.. teredo, isatap and 6to4

                  Simple reg key will turn it all off.
                  From admin prompt
                  reg add hklm\system\currentcontrolset\services\tcpip6\parameters /v DisabledComponents /t REG_DWORD /d 255

                  reboot.. To put it back just delete the key
                  reg delete hklm\system\currentcontrolset\services\tcpip6\parameters\ /v DisabledComponents /f

                  Reboot and your back to how it was out of the box.. Everything on teredo, isatap, 6to4

                  If not running windows and running a flavor of linux/bsd it might also be possible to disable the link local, etc.

                  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
                  • M
                    mscaff
                    last edited by

                    Can a link local be used to identity a host/person globally? Or is it similar to 192/172/10.0 networking?

                    Can a v6 address also leak through a VPN with v6 turned off and compromise anonymity?

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

                      Hmmm…

                      That Browser Leaks site doesn't like IPv6.

                      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
                      • JKnottJ
                        JKnott
                        last edited by

                        Can a link local be used to identity a host/person globally? Or is it similar to 192/172/10.0 networking?

                        A link local address can only be used to identify a piece of hardware.  It has absolutely no info about who or where you are.  It's normally based on the MAC address.

                        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
                        • johnpozJ
                          johnpoz LAYER 8 Global Moderator
                          last edited by

                          @JKnott - it was just the first site I found with a quick google to just show that browser can leak your local address.  It might not even do IPv6, etc.

                          Without some details its unclear to what might have been reported to this guys buddy.  But if he has ipv6 off on pfsense, I find it pretty much impossible for it to be a global IPv6 address from his isp, etc.  So it could be something like a browser leak, or could be say a teredo address..

                          There are better sites for detecting ipv6 leaks, etc.

                          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
                          • First post
                            Last post
                          Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.