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    NAT forwarding into WireGuard Interface as LAN Interface

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    • B
      Bronko @viragomann
      last edited by

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

      You should find tun_wg0 in Status > Interface. Then it's a dedicated interface.

      Yes, it is already there due to the WireGurad setup.

      Thanks @viragomann !

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

        @viragomann

        On Site-B at server net one machineMX is configured like these:

        # netstat -rn
        Kernel IP routing table
        Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
        0.0.0.0         10.200.0.2      0.0.0.0         UG        0 0          0 eth0
        10.0.0.0        0.0.0.0         255.255.255.0   U         0 0          0 eth0
        10.200.0.2      10.0.0.1        255.255.255.255 UGH       0 0          0 eth0
        10.200.0.2      0.0.0.0         255.255.255.255 UH        0 0          0 eth0
        
        # ip addr
        1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
            link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
            inet 127.0.0.1/8 scope host lo
               valid_lft forever preferred_lft forever
            inet6 ::1/128 scope host 
               valid_lft forever preferred_lft forever
        2: eth0@if36: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
            link/ether 82:08:92:77:f8:80 brd ff:ff:ff:ff:ff:ff link-netnsid 0
            inet 10.0.0.102/24 brd 10.0.0.255 scope global eth0
               valid_lft forever preferred_lft forever
            inet6 fe80::8008:92ff:fe77:f880/64 scope link 
               valid_lft forever preferred_lft forever
        
        # ping 10.200.0.2
        PING 10.200.0.2 (10.200.0.2) 56(84) bytes of data.
        64 bytes from 10.200.0.2: icmp_seq=1 ttl=63 time=25.4 ms
        64 bytes from 10.200.0.2: icmp_seq=2 ttl=63 time=25.5 ms
        64 bytes from 10.200.0.2: icmp_seq=3 ttl=63 time=25.3 ms
        

        But outgoing internet traffic doesn't goes through Site-A tun_wg0: 10.200.0.2

        # curl ifconfig.me
        curl: (7) Failed to connect to ifconfig.me port 80 after 3093 ms: No route to host
        

        HAproxy on Site-A managed incoming traffic as awaited, but on machineMX initiated internet connections (like postfix) on Site-B should go on WAN interface at Site-A.

        Outbound NAT for masquerading at Site-A for servers IP at Site-B temporarily (HAproxy doesn't need it as you mentioned above) activated, but doesn't changed the behavior.

        There are some routing/gateway configuration steps in Site-B still open for these scenario?

        Do you have some hints here too?

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

          @Bronko TLDR but I have that running now, what you have described at first and I don't see any problems. I don't NAT anything inside this whole network, only towards public addresses on WAN.
          Also make sure that on B the peer-config off A has 0.0.0.0/0 as allowed IPs and that in A all the routes are set in System-Routing-Static Routes.

          B 2 Replies Last reply Reply Quote 1
          • B
            Bronko @Bob.Dig
            last edited by Bronko

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

            Also make sure that on B the peer-config off A has 0.0.0.0/0 as allowed IPs...

            That was missing!
            Thanks to @Bob-Dig

            But machineMX doesn't knows anymore tun_wg0: 10.200.0.2 for routing (DNS only), solved by Policy Routing on Site-B as described here for ex.

            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:

              @Bronko TLDR but I have that running now, what you have described at first and I don't see any problems. I don't NAT anything inside this whole network, only towards public addresses on WAN.

              Routing is fine, but I have to see the source IP address of sending mail server at the internet on machineMX on Site-B server net (10.0.0.0/24). Currently the 10.200.0.2 (tun_wg0) is present because of NAT.

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

              This replaces the source IP anyway.

              You are right, the source IP is replaced by 10.200.0.2 (tun_wg0). How to avoid it?

              Any hints for me?

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

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

                Any hints for me?

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

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

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

                  This replaces the source IP anyway.
                  

                  You are right, the source IP is replaced by 10.200.0.2 (tun_wg0). How to avoid it?

                  HAproxy has to replace the source IP with its outgoing interface IP to get the routing work reliably.

                  You can avoid this though by enabling the transparent mode in the concerned backend settings. But I don't know if the routing across the VPN will work properly then.
                  Anyway you would have to obey my suggestions regarding interface assignment and filter rules at B above.

                  If it's a http frontend it's rather recommended to add a forward-for header, which would get the clients IP as value. However, the backend server would have to interpret this to get the client IP in the log.

                  B 1 Reply Last reply Reply Quote 0
                  • B
                    Bronko @viragomann
                    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.

                    That is what I have learned here, using haproxy for SMTP isn't comfortable...

                    Therefore I have been already created a forwarding rule for WAN on Site-A to machineMX on Site-B server net (10.0.0.0/24) and re-configured the mapping suggested by:

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

                    So configure the outbound NAT for masquerading at A even now.

                    Activate the hybrid mode, save this and add a new rule:
                    interface: tun_wg0 (or whatever the WG is)
                    protocol: TCP (or what you forward)
                    source: any
                    destination: the servers IP at B or an alias for multiple destination IPs
                    translation: interface address

                    by the option Do not NAT. But these option breaks the traffic flow, no more connection from outside to SMTP on machineMX.

                    What I have to learn here...?

                    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:

                      by the option Do not NAT. But these option breaks the traffic flow, no more connection from outside to SMTP on machineMX.

                      I didn't mention that option.
                      And the NAT might be superfluous if you're driving this traffic over HAproxy, as mentioned. The suggestion was meant for the time to be.

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

                        Just to recap, you have a VPS in the internet, just with pfSense on it.
                        At home you have a pfSense too and an email-server behind that.
                        You have made a WireGuard tunnel between the two sites.

                        Now what you can do is a port 25 forward from the VPS to your email-server at home. Also you can route outgoing traffic to port 25 using the VPS over that WG tunnel.

                        Have a look at this video how to do a Site-to-Site VPN Using WireGuard and pfSense even if you don't have any other hosts on the VPS.

                        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:

                          I didn't mention that option.

                          I know, but it was my first run to disable NAT for a specific connection only, to avoid to disable NAT entirely given by the fact not only public routable interfaces on pfsense at Site-A.

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

                          Just to recap, you have a VPS in the internet, just with pfSense on it.
                          At home you have a pfSense too and an email-server behind that.
                          You have made a WireGuard tunnel between the two sites.

                          Perfect recap!

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

                          Now what you can do is a port 25 forward from the VPS to your email-server at home. Also you can route outgoing traffic to port 25 using the VPS over that WG tunnel.

                          Exactly my current configuration with NAT enabled at VPS (Site-A here).

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

                          Have a look at this video how to do a Site-to-Site VPN Using WireGuard and pfSense even if you don't have any other hosts on the VPS.

                          Already done.

                          (and mentioned here:)
                          @Bronko said in NAT forwarding into WireGuard Interface as LAN Interface:

                          But machineMX doesn't knows anymore tun_wg0: 10.200.0.2 for routing (DNS only), solved by Policy Routing on Site-B as described here for ex.

                          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?

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

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

                            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?

                            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...

                            B 1 Reply Last reply Reply Quote 0
                            • 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.

                                    1 Reply Last reply Reply Quote 0
                                    • 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
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