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

    Bogons

    Scheduled Pinned Locked Moved Firewalling
    9 Posts 3 Posters 1.2k Views 3 Watching
    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.
    • GilG Offline
      Gil Rebel Alliance
      last edited by

      I swapped my DSL Modem for a 4G modem (with ethernet port),then updated the DYNDNS.
      I found that I could not connect via OpenVPN, and it appears to be due to blocking of bogons on the WAN port.
      The OpenVPN client is also on 4G, but not with a publicly accessible IP Address.
      Does that sound usual?

      11 cheers for binary

      1 Reply Last reply Reply Quote 0
      • jimpJ Offline
        jimp Rebel Alliance Developer Netgate
        last edited by

        Most likely your WAN IPv4 address on 4G will be carrier grade NAT, meaning you have no means to accept inbound connections from the Internet, so you can't run an OpenVPN server on that connection.

        You might be able to use IPv6 for that, or maybe pay the ISP more for a true public IPv4 address.

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

        Need help fast? Netgate Global Support!

        Do not Chat/PM for help!

        GilG 1 Reply Last reply Reply Quote 0
        • GilG Offline
          Gil Rebel Alliance @jimp
          last edited by

          @jimp
          The 4G modem that hosts the OpenVPN (pfSense) Server is provisioned with a true public IP address, which functions correctly. (and is essential for DynDNS to work).

          What I noticed is: I could not connect via an Android OpenVPN connection which is also on 4G but on a carrier grade NAT. - Unless I turn off the Bogon Block on the WAN Interface.

          To further test it; I changed the APN on my Android client to get a public IP address - and the Android OpenVPN connected - with Bogon Block enabled on the WAN.

          It appears that Bogon Block can hamper OpenVPN connections from clients that are connected on Carrier Grade NATs.
          This is the first time I have noticed it and it appears to happen when the Server ISP is also on the same 4G network, even though it has a publicly accessible IPv4 address.

          11 cheers for binary

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

            What IP were you coming from? Yes if it was in the bogon list it would be blocked. But IPs in bogon should not be in there if they are not bogon. Your carrier could not be using bogon if they wanted to talk to other things on the interent since bogon are not suppose to route.

            So what was the IP you were coming from when being blocked with bogon, and we can look to see if your bogon list is just no updated or if your carrier is doing something borked trying to use bogon networks, 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 25.07.1 | Lab VMs 2.8.1, 25.07.1

            1 Reply Last reply Reply Quote 0
            • GilG Offline
              Gil Rebel Alliance
              last edited by

              The IP's seem a little strange.
              1.144.106.254 is the IP prior to connecting according to 'myip'
              IPs that appear when Bogon blocks are turned off include:
              100.102.114.115, and
              100.100.97.92
              (These are the reported IP's on the OpenVPN status)

              11 cheers for binary

              jimpJ 1 Reply Last reply Reply Quote 0
              • jimpJ Offline
                jimp Rebel Alliance Developer Netgate @Gil
                last edited by

                @gil said in Bogons:

                The IP's seem a little strange.
                1.144.106.254 is the IP prior to connecting according to 'myip'

                That's an actual public address, but your DynDNS would probably say that even if your WAN was in CGN since it usually would poll the address from an outside source if it sees a private address on the interface.

                IPs that appear when Bogon blocks are turned off include:
                100.102.114.115, and
                100.100.97.92
                (These are the reported IP's on the OpenVPN status)

                Those are both in the carrier grade NAT block, 100.64.0.0/10. If you are both on the same ISP, it's possible they route connections internally between hosts before passing them through CGN.

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

                Need help fast? Netgate Global Support!

                Do not Chat/PM for help!

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

                  As jim stated those are in the CGN space

                  "Comment: Shared Address Space can only be used in Service Provider networks or on routing equipment that is able to do address translation across router interfaces when addresses are identical on two different interfaces. "

                  So yeah if your coming from that address space and your wan actually has an IP in that range.. Then you would need to remove it from bogon for your use, or just turn off bogon all together for that to work.

                  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 25.07.1 | Lab VMs 2.8.1, 25.07.1

                  GilG 1 Reply Last reply Reply Quote 0
                  • GilG Offline
                    Gil Rebel Alliance @johnpoz
                    last edited by

                    @johnpoz said in Bogons:

                    So yeah if your coming from that address space and your wan actually has an IP in that range… Then you would need to remove it from bogon for your use, or just turn off bogon all together for that to work.

                    I have simply turn off Bogon Blocking, but are you saying there is a way to remove these addresses from my own individual Bogon list? How do I edit it?

                    I also agree with jimp in the assessment of the carrier doing internal routes from internal 4G to 4G; This issue disappears when I replace the server WAN with a different ISP. (The carrier is Telstra in Australia FYI).

                    11 cheers for binary

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

                      You could edit the source code that updates the bogon table - it already removes rfc1918

                      https://github.com/pfsense/pfsense/blob/b8f91b7c6bd16602d49f50c47f4ea28649404c97/src/etc/rc.update_bogons.sh

                      egrep -v "^192.168.0.0/16|^172.16.0.0/12|^10.0.0.0/8" /tmp/bogons > /etc/bogons

                      So sure you could edit that to pull out other networks, just keep in mind that on an update to pfsense your changes would get overwrote unless you created a patch that gets applied.

                      Not something I recommend, but sure can be done. I don't know of a gui way - but then again have not looked into doing that before.

                      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 25.07.1 | Lab VMs 2.8.1, 25.07.1

                      1 Reply Last reply Reply Quote 1
                      • First post
                        Last post
                      Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.