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    NAT forwarding into WireGuard Interface as LAN Interface

    Scheduled Pinned Locked Moved Firewalling
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    • V
      viragomann @Bronko
      last edited by

      @Bronko said in NAT forwarding into WireGuard Interface as LAN Interface:

      Resuming:
      How to disable NAT for these specific SMTP traffic flow to log real source IP of connecting mail server - currently replaced by 10.200.0.2 (tun_wg0 at Site-B) - at my machineMX?

      If you direct this connection over HAproxy read again, what I wrote above.

      1 Reply Last reply Reply Quote 0
      • B
        Bronko @Bob.Dig
        last edited by

        @Bob-Dig said in NAT forwarding into WireGuard Interface as LAN Interface:

        Please show your Port Forward on your VPS and also the config of your WG Interface for both. Outbound NAT for both should be automatic, nothing else. It is that easy...

        Site-A (VPS):

        Screenshot from 2023-10-05 21-42-58.png

        Screenshot from 2023-10-05 21-47-45.png

        Screenshot from 2023-10-05 21-48-57.png

        Site-B (home):

        Screenshot from 2023-10-05 21-50-34.png

        Screenshot from 2023-10-05 21-51-54.png

        As mentioned, mail server at home - machineMX (at LAN_SEITE3) - is working for in- and outbound mails, but the replaced source ip of incomming mail server connections.

        @viragomann said in NAT forwarding into WireGuard Interface as LAN Interface:

        If you direct this connection over HAproxy read again, what I wrote above.

        Will double check it but to use HAProxy as a reverse proxy for the Postfix SMTP server, you need to enable Postscreen in Postfix. This doesn't worked for me at the first run...

        Bob.DigB B 2 Replies Last reply Reply Quote 0
        • Bob.DigB
          Bob.Dig LAYER 8 @Bronko
          last edited by Bob.Dig

          @Bronko I meant the complete IP-config from those interfaces, not their status.
          Also remove the manual outbound NAT rule and forget haproxy.
          And what rule is the last one? For the tunnel use an allow any rule for testing.

          B 1 Reply Last reply Reply Quote 0
          • B
            Bronko @Bob.Dig
            last edited by Bronko

            @Bob-Dig said in NAT forwarding into WireGuard Interface as LAN Interface:

            I meant the complete IP-config from those interfaces, not their status.

            The tunnel is working fine, no problem here... isn't it?

            @Bob-Dig said in NAT forwarding into WireGuard Interface as LAN Interface:

            Also remove the manual outbound NAT rule and forget haproxy.

            Without this rule @viragomann (above) incomming conntections via VPS at Site-A to machineMX at Site-B doesn't work.

            @Bob-Dig said in NAT forwarding into WireGuard Interface as LAN Interface:

            And what rule is the last one? For the tunnel use an allow any rule for testing.

            An allow any rule for wg_tunnel is in place. These last one is policy routing for server net (LAN_SEITE3). Without these the outgoing traffic at server net is routed via default gateway at Site-A.

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            • B
              Bronko @Bronko
              last edited by Bronko

              Let's have a picture here, port forwarding, outbound NAT and policy routing via rules from above:

              Untitled.jpg

              Described above:

              Site-A

              tun_wg0: 10.200.0.2

              netstat -rn
              Routing tables
              
              Internet:
              Destination        Gateway            Flags     Netif Expire
              default            xxxxxxxxxx         UGS      vtnet0
              10.0.0.0/24        10.200.0.1         UGS     tun_wg0
              10.200.0.0/24      link#6             U       tun_wg0
              10.200.0.2         link#3             UHS         lo0
              xxxxxxxxx/22       link#1             U        vtnet0
              xxxxxxxxx          link#3             UHS         lo0
              yyyyyyyyyyyyy      link#1             UHS      vtnet0
              yyyyyyyyyyyyy      link#1             UHS      vtnet0
              127.0.0.1          link#3             UH          lo0
              192.168.0.0/16     10.200.0.1         UGS     tun_wg0
              
              

              Screenshot from 2023-07-04 18-40-47.png

              Site-B

              tun_wg0: 10.200.0.1

              netstat -rn
              Routing tables
              
              Internet:
              Destination        Gateway            Flags     Netif Expire
              0.0.0.0/8          link#12            U         re0.8
              default            xxxxxxxxxxxxx      UGS      pppoe0
              10.0.0.0/24        link#18            U       re2.301
              10.0.0.1           link#5             UHS         lo0
              10.0.1.0/24        link#21            U        ovpns1
              10.0.1.1           link#5             UHS         lo0
              10.0.2.0/24        link#25            U        ovpns2
              10.0.2.1           link#5             UHS         lo0
              10.0.3.0/24        link#22            U        ovpns3
              10.0.3.1           link#5             UHS         lo0
              10.0.4.0/24        link#23            U        ovpns5
              10.0.4.1           link#5             UHS         lo0
              10.0.5.0/24        link#24            U        ovpns6
              10.0.5.1           link#5             UHS         lo0
              10.200.0.0/24      link#8             U       tun_wg0
              10.200.0.1         link#5             UHS         lo0
              xxxxxxxxxxxxxx     link#19            UH       pppoe0
              yyyyyyyyyyyyy      link#5             UHS         lo0
              127.0.0.1          link#5             UH          lo0
              192.168.1.0/24     link#2             U           re1
              192.168.1.1        link#5             UHS         lo0
              192.168.2.0/30     link#1             U           re0
              192.168.2.2        link#5             UHS         lo0
              192.168.3.0/24     link#17            U       re2.106
              192.168.3.1        link#5             UHS         lo0
              192.168.6.0/24     link#20            U       bridge0
              192.168.6.1        link#5             UHS         lo0
              192.168.8.0/24     link#10            U       re2.201
              192.168.8.1        link#5             UHS         lo0
              192.168.9.0/24     link#16            U       re2.105
              192.168.9.1        link#5             UHS         lo0
              192.168.21.0/24    10.0.2.2           UGS      ovpns2
              192.168.178.0/24   10.0.4.2           UGS      ovpns5
              192.168.179.0/24   10.0.5.2           UGS      ovpns6
              zzzzzzzzzzzzzz     link#19            UHS      pppoe0
              
              

              Screenshot from 2023-07-04 18-47-12.png

              Server on Site-B (first post) located at 10.0.0.0/24

              machineMX log for incomming smtp connection:

              postfix/smtpd[31491]: connect from mail.example.org[10.200.0.2]
              

              How to disable NAT to achieve this?:

              postfix/smtpd[31491]: connect from mail.example.org[...real_IP...]
              
              B 1 Reply Last reply Reply Quote 0
              • B
                Bronko @Bronko
                last edited by Bronko

                @Bob-Dig said in NAT forwarding into WireGuard Interface as LAN Interface:

                Don't NAT, like I said before and don't use haproxy for email.

                Ok, but NAT on Site-A WAN interface is necessary for sure.

                @viragomann said in NAT forwarding into WireGuard Interface as LAN Interface:

                Anyway you would have to obey my suggestions regarding interface assignment and filter rules at B above.

                I'm full in trust with you and and it's right in place....

                V 1 Reply Last reply Reply Quote 0
                • V
                  viragomann @Bronko
                  last edited by

                  @Bronko said in NAT forwarding into WireGuard Interface as LAN Interface:

                  what I would like to reach?

                  Still not clear, what this is and what you're doing exactly, even I requested several times. So I'm out here.

                  B 1 Reply Last reply Reply Quote 0
                  • B
                    Bronko @viragomann
                    last edited by Bronko

                    @viragomann said in NAT forwarding into WireGuard Interface as LAN Interface:

                    Still not clear, what this is and what you're doing exactly, even I requested several times. So I'm out here.

                    Oh, I'm sorry... my picture above should it sum up.
                    Recap: How to log on machineMX real source IP here:

                    postfix/smtpd[31491]: connect from mail.example.org[...real_IP...]
                    
                    B 1 Reply Last reply Reply Quote 0
                    • B
                      Bronko @Bronko
                      last edited by

                      I have been take some packet sniffs...

                      With outbound NAT rule @viragomann from above the source IP is replaced by pfsense tun_wg0 at Site-A (10.200.0.2) and machineMX reply is flowing back to Site-A; it works.

                      Without outbound NAT the real source IP is kept (what I would like to reach) and the machineMX is replying too (sniffed at LAN_SEITE3), but the reply doesn't dive into tun_wg0 back at Site-B, means only the smtp requests from real source IP are sniffed at tun_wg0. No firewall drops in system logs. "Allow any rules" are placed at tunnel and server net (LAN_SEITE3) as required.
                      How can I find where the smtp replies are dropped?

                      V 1 Reply Last reply Reply Quote 0
                      • V
                        viragomann @Bronko
                        last edited by

                        @Bronko
                        You mentioned above, that you run the SMTP traffic over HAproxy at A. Is that still the case???

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                        • B
                          Bronko @Bronko
                          last edited by

                          @viragomann
                          No isn't:

                          @Bronko said in NAT forwarding into WireGuard Interface as LAN Interface:

                          .... but to use HAProxy as a reverse proxy for the Postfix SMTP server, you need to enable Postscreen in Postfix. This doesn't worked for me at the first run...

                          SMTP port forwarding for now, and it only works with outbound NAT rule at Site-A... (my last post).

                          B 1 Reply Last reply Reply Quote 0
                          • B
                            Bronko @Bronko
                            last edited by Bronko

                            Because I'm going off topic here, I'm resuming what is still the problem at a new Topic and it solved there.

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