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

    Access network behind a double NAT?

    Scheduled Pinned Locked Moved NAT
    14 Posts 6 Posters 2.0k 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.
    • R
      riahc8
      last edited by

      Hello

      I have plenty of ports on my pfSense so I wanted to know if its possible to access the devices some way that are in the NAT behind the double NAT setup.

      V 1 Reply Last reply Reply Quote 0
      • R riahc8 referenced this topic on
      • V
        viragomann @riahc8
        last edited by

        @riahc8
        Yes, if you have a public IP and forward incoming traffic on both routers.

        R 1 Reply Last reply Reply Quote 0
        • R
          riahc8 @viragomann
          last edited by

          @viragomann said in Access network behind a double NAT?:

          @riahc8
          Yes, if you have a public IP and forward incoming traffic on both routers.

          Can you be specific?

          S V 2 Replies Last reply Reply Quote 0
          • S
            SteveITS Galactic Empire @riahc8
            last edited by

            @riahc8 ISP router forwards the port to pfSense. PfSense forwards the port to your web server.
            Many ISP routers can be configured to send all ports to one IP often called its DMZ.

            Pre-2.7.2/23.09: Only install packages for your version, or risk breaking it. Select your branch in System/Update/Update Settings.
            When upgrading, allow 10-15 minutes to restart, or more depending on packages and device speed.
            Upvote 👍 helpful posts!

            1 Reply Last reply Reply Quote 0
            • V
              viragomann @riahc8
              last edited by

              @riahc8
              Regarding public IP, some ISPs give you only a private IPv4 within their network (CG-NAT). This cannot be reached from the internet. Hence your network would not be accessible from outside in this case.
              Maybe you can use an IPv6 to access it, however.

              So for IPv4 access, ensure that your ISP router gets a real public IP.

              R 1 Reply Last reply Reply Quote 0
              • R
                rcoleman-netgate Netgate @viragomann
                last edited by

                @viragomann And in those cases a MITM VPN might be the only solution... Using a cloud provider you can do re-routing but for large amounts of data that can be very expensive.

                Ryan
                Repeat, after me: MESH IS THE DEVIL! MESH IS THE DEVIL!
                Requesting firmware for your Netgate device? https://go.netgate.com
                Switching: Mikrotik, Netgear, Extreme
                Wireless: Aruba, Ubiquiti

                1 Reply Last reply Reply Quote 0
                • R
                  riahc8
                  last edited by riahc8

                  ad285ae9-d508-494e-963e-5afc970fbf23-image.png

                  Here is a SIMPLE diagram.

                  With this double NAT I want PC to access PC2 (and/or visaversa)

                  Would it be possible to do this?

                  keyserK S 2 Replies Last reply Reply Quote 0
                  • keyserK
                    keyser Rebel Alliance @riahc8
                    last edited by

                    @riahc8 Yes, if the ISP router has a public IP and you can configure it to portforward to your pfSense. After that you configure your pfSense to portforward to your PC. But it’s a pretty “dodgy” setup.

                    This is one of the reasons many of us replace the ISP router with pfSense directly - but that too can be a hassle.

                    Love the no fuss of using the official appliances :-)

                    1 Reply Last reply Reply Quote 0
                    • S
                      SteveITS Galactic Empire @riahc8
                      last edited by

                      @riahc8 Not seeing PC2 in the diagram?

                      Connecting inbound from the Internet is as described above. Connecting out to the Internet from PC will “just work” nothing to do.

                      Pre-2.7.2/23.09: Only install packages for your version, or risk breaking it. Select your branch in System/Update/Update Settings.
                      When upgrading, allow 10-15 minutes to restart, or more depending on packages and device speed.
                      Upvote 👍 helpful posts!

                      R 1 Reply Last reply Reply Quote 0
                      • R
                        riahc8 @SteveITS
                        last edited by riahc8

                        @SteveITS said in Access network behind a double NAT?:

                        @riahc8 Not seeing PC2 in the diagram?

                        Connecting inbound from the Internet is as described above. Connecting out to the Internet from PC will “just work” nothing to do.

                        I posted the image like 10 times. The forums bugged out. Updated the diagram

                        Both PC and PC2 have internet access

                        S V 2 Replies Last reply Reply Quote 0
                        • S
                          SteveITS Galactic Empire @riahc8
                          last edited by

                          @riahc8 With PC2 on the LAN side of the ISP router it’s just one port forward.

                          Source: .22.56 (or .22.0/24 for all devices)
                          Source port: any
                          Forward to .9.7

                          PC can connect to .22.56 directly.

                          Pre-2.7.2/23.09: Only install packages for your version, or risk breaking it. Select your branch in System/Update/Update Settings.
                          When upgrading, allow 10-15 minutes to restart, or more depending on packages and device speed.
                          Upvote 👍 helpful posts!

                          R 1 Reply Last reply Reply Quote 0
                          • V
                            viragomann @riahc8
                            last edited by

                            @riahc8
                            So from the internet to PC2 you only a single NAT. Why do you speaking about double?

                            However, consider that you can forward a single IP + port to only one backend device. So if you have only one public IP you can forward e.g. port 443 on only one internal host.

                            1 Reply Last reply Reply Quote 0
                            • R
                              riahc8 @SteveITS
                              last edited by

                              @SteveITS said in Access network behind a double NAT?:

                              @riahc8 With PC2 on the LAN side of the ISP router it’s just one port forward.

                              Source: .22.56 (or .22.0/24 for all devices)
                              Source port: any
                              Forward to .9.7

                              PC can connect to .22.56 directly.

                              No no, Im not looking for just a port foward.

                              Anything on the .22/24 and .9/24 should be able to access each other, both ways.

                              the otherT 1 Reply Last reply Reply Quote 0
                              • the otherT
                                the other @riahc8
                                last edited by

                                @riahc8 hey there,
                                shouldn't it be enough to work with rules?
                                iE
                                IF WAN allow WAN Net (network between pfsense and ISP router), all port, destination IP PC
                                IF LAN allow LAN Net (or just IP pc), all port, destination WAN Net (or just IP PC2).

                                That way, pfsense allows connecting net with pc (LAN) to net with pc2 (WAN) and vice versa. If that works, reconfigure so only the needed ports are allowed (and only needed clients in those nets).

                                Or did the heat here damage my brain?
                                :)

                                the other

                                pure amateur home user, no business or professional background
                                please excuse poor english skills and typpoz :)

                                1 Reply Last reply Reply Quote 0
                                • First post
                                  Last post
                                Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.