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    Redirecting LAN DNS

    Scheduled Pinned Locked Moved DHCP and DNS
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    • M
      McMurphy @johnpoz
      last edited by

      @johnpoz

      pfSense: 192.168.2.254
      29.03.2024_17.49.30_REC.png

      I tried to adapt the guide to what I wanted. Following what is in the green box I get:
      29.03.2024_17.56.45_REC.png

      I can't use the pfSense DNS as I need to ensure all queries are resolved by 100.96.1.1 (DNS filtering service) so I am looking for an alternative.

      M johnpozJ M 3 Replies Last reply Reply Quote 0
      • M
        MoonKnight @McMurphy
        last edited by MoonKnight

        @McMurphy
        Are you behind CGNAT?
        Since your DNS is in the RFC6598
        100.64.0.0 - 100.127.255.255

        Why not put some other DNS servers in the "General Setup"
        Are you ISP blocking you for using other DNS servers?

        Or, maybe this one is blocking you?
        1880e92b-8764-451a-9c05-db4b8697231a-image.png

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        • johnpozJ
          johnpoz LAYER 8 Global Moderator @McMurphy
          last edited by

          @McMurphy you show your port forward where are you firewall rules on the interface?

          So you want this 100.96.1.1 to resolve all your external dns then? Just forward to it. And block all your other dns..

          Now that your saying hey anything but 100.96.1.1 forward to loopback, does unbound forward to this 100.96?

          In your previous example if pfsense is 192.168.2.254, that would be the lan address. So your ! lan address wouldn't have applied..

          100.96 as @MoonKnight is pointing out is cgnat - seems like an odd dns to use that filters, since the only way to talk to that IP would be on the isp network that is using that cgnat..

          Also if your forwarding to this 100.96 address, and it sends back rfc1918, that 192.168.1.12 that would be a rebind, and no psfense would hand you that address unless you turned off rebind protection for that domain. Which is why a directed query would work, but pfsense forwarding to it would not..

          I take it your domain your hiding is public - having rfc1918 address space in public dns is going to be problematic that is for sure, and is not good practice.

          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
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          • M
            McMurphy @McMurphy
            last edited by

            @McMurphy

            I can put other DNS servers in the DNS server list however I need all LAN traffic to use the private DNS server that is only available over the OVPN link.

            Catch 22:

            • pfSense needs access to a public DNS server to establish the OVPN link
            • All client devices are to only use the private DNS server
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            • M
              McMurphy @johnpoz
              last edited by

              @johnpoz said in Redirecting LAN DNS:

              @McMurphy you show your port forward where are you firewall rules on the interface?

              So you want this 100.96.1.1 to resolve all your external dns then? Just forward to it. And block all your other dns..

              Then pfSense is unable to establish the OVPN link and until established 100.96.1.1 is unavailale

              Also if your forwarding to this 100.96 address, and it sends back rfc1918, that 192.168.1.12 that would be a rebind, and no psfense would hand you that address unless you turned off rebind protection for that domain. Which is why a directed query would work, but pfsense forwarding to it would not..

              I have worked out how to disable to rebind and this works however if traffic goes through pfSense to 100.96.1.1 as a Forwarder then I still need a public DNS for the OVPN link to be initially established

              I take it your domain your hiding is public - having rfc1918 address space in public dns is going to be problematic that is for sure, and is not good practice.

              Not at all. I simply have a LAN behind a pfSense router and a DNS filtering service that is accessible via an OVPN link on pfSense. I want everything to function like normal but just use the 100.96.1.1 dns server to filter the DNS requests.

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

                @McMurphy said in Redirecting LAN DNS:

                I have worked out how to disable to rebind

                https://docs.netgate.com/pfsense/en/latest/services/dns/rebinding.html

                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

                M 1 Reply Last reply Reply Quote 0
                • M
                  McMurphy @johnpoz
                  last edited by

                  @johnpoz

                  Yes. I can disable rebind when I use either the Resolver or Forwarder however these do not allow me to force DNS down the private OVPN DNS server.

                  I have read about policy routing but an not sure how it works.

                  A solution would be to have either:
                  a) all DNS queries sent to the private OVPN DNS server 100.96.1.1
                  b) all DNS queries sent over the OVPN interface

                  Can this be achieved with policy routing?

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

                    @McMurphy yes policy routing is how you send a client down a specific gateway, be that a normal gateway or some vpn connection.

                    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

                    M 1 Reply Last reply Reply Quote 0
                    • M
                      McMurphy @johnpoz
                      last edited by

                      @johnpoz

                      I believe I have two possible solutions Not sure which is best and if there are quicks with either I have not thought of:

                      a) Use policy routing to send all DNS over the VPN
                      30.03.2024_17.27.40_REC.png

                      b) Use NAT to redirect all DNS enquiries to 100.96.1.1
                      30.03.2024_17.26.30_REC.png

                      My preference is (b) if that'll work as expected as the IP 100.96.1.1 will automatically be routed over the VPN

                      M 1 Reply Last reply Reply Quote 0
                      • M
                        MoonKnight @McMurphy
                        last edited by

                        @McMurphy

                        I found this, probably not what you are looking for. But if you are using CloudConnexa as your VPN provider, then I thing you need to change your NAT rule. Try to remove the destination address.
                        https://openvpn.net/cloud-docs/tutorials/configuration-tutorials/connectors/routers/tutorial--configure-a-pfsense-router-to-connect-to-cloudconnexa.html

                        --- 24.11 ---
                        Intel(R) Xeon(R) CPU D-1518 @ 2.20GHz
                        Kingston DDR4 2666MHz 16GB ECC
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                        2 x Intel i210 (ports)
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