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

    Two pfsense boxes walk into a bar...

    Scheduled Pinned Locked Moved General pfSense Questions
    22 Posts 4 Posters 2.3k Views 4 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.
    • EveningStarNME Offline
      EveningStarNM @stephenw10
      last edited by

      @stephenw10 Have you ever seen a private network connected as a client to another?

      I really don't understand why this configuration appears to be so strange to some. Perhaps if I'd re-arranged the figures, it would have been more recognizable as an exercise in some CS200-level class.

      johnpozJ stephenw10S 2 Replies Last reply Reply Quote 0
      • johnpozJ Offline
        johnpoz LAYER 8 Global Moderator @EveningStarNM
        last edited by

        @eveningstarnm said in Two pfsense boxes walk into a bar...:

        really don't understand why this configuration appears to be so strange to some.

        I showed you in the picture! It is asymmetrical!

        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

        EveningStarNME 1 Reply Last reply Reply Quote 0
        • stephenw10S Offline
          stephenw10 Netgate Administrator @EveningStarNM
          last edited by

          @eveningstarnm said in Two pfsense boxes walk into a bar...:

          @stephenw10 Have you ever seen a private network connected as a client to another?

          Many times and quite often using a similar setup to this. And usually it's when people open a ticket with us to determine why they are seeing connection issues. It almost always because of asymmetric traffic being blocked in 'pfSense 1' in your diagram because it only sees half the TCP conversation.
          You would find it connectivity comes in and out as the first firewall sends an ICMP redirect the host allowing it to work for a short time until it expires. Typically ~30s. It fits what you initially described perfectly.
          The only we to avoid that without using a transport subnet (which is the correct way to do it) is to add specially configured firewall rules:
          https://docs.netgate.com/pfsense/en/latest/troubleshooting/asymmetric-routing.html#manual-fix

          Steve

          EveningStarNME 1 Reply Last reply Reply Quote 0
          • EveningStarNME Offline
            EveningStarNM @johnpoz
            last edited by EveningStarNM

            @johnpoz Yes, it's asymetrical. One network is a client of another. IT'S SUPPOSED TO BE THAT WAY. But I won't explore here the myriad use cases in which such a design is not only employed but expected.

            johnpozJ 1 Reply Last reply Reply Quote 0
            • EveningStarNME Offline
              EveningStarNM @stephenw10
              last edited by

              @stephenw10 They're different networks with different purposes. They are not peers. In fact, not every device from the two networks are allowed to talk to each other. In that regard, it's kind of like the entire internet.

              One network is a client of another. If you want to solve a different problem, you should start your own thread. The one you know how to solve isn't related to this one.

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

                @eveningstarnm said in Two pfsense boxes walk into a bar...:

                IT'S SUPPOSED TO BE THAT WAY

                Says who - you? It is NOT suppose to be that way.. Already went over all the hoops you have to go through to use it like that..

                If you want to run such setup - have fun with it. Couple of minutes to actually create a valid transit network and you wouldn't have to.

                You know who runs networks like that - people that don't know any better..

                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

                EveningStarNME 1 Reply Last reply Reply Quote 0
                • EveningStarNME Offline
                  EveningStarNM @johnpoz
                  last edited by EveningStarNM

                  @johnpoz Dude. Please avoid my threads. I see no indication that you could be at all helpful to me. You insist on telling me how our networks should be designed when you don't even know how they're related or what they're used for. Those networks don't even have the same TLD. They're different networks with different purposes, and they are not related the way you want them to be. If they were, they would not suit our needs. One is simply using a service that the other provides.

                  I described the problem. I even found the solution. Your comments have been irrelevant and a total waste of time. I'm blocking you again. The years I spent here not seeing your comments were good ones.

                  Update: As it turns out, I can't re-block you. I should never have unblocked you.

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

                    @eveningstarnm good luck! I don't care how you want to use or or intend to use it. Using a network with hosts on it as transit, which is any network that connects routers together.. Is not the proper way to do it.. Sorry but its not..

                    Can you do it sure - but if you plan on talking to these hosts on this transit - its going to be problematic without the work arounds given, natting or host routing. You were even given a pretty picture showing how traffic will be asymmetrical. But clearly you know better..

                    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

                    EveningStarNME 1 Reply Last reply Reply Quote 0
                    • EveningStarNME Offline
                      EveningStarNM @johnpoz
                      last edited by

                      @johnpoz I don't need luck. I solved the problem, and it's working great. Nothing that you said was helpful.

                      1 Reply Last reply Reply Quote 0
                      • stephenw10S Offline
                        stephenw10 Netgate Administrator
                        last edited by

                        Reviewing this I assume that, effectively, pfSense 2 in your diagram is using pfSense 1 as second WAN?

                        If it's only using it for that it will work fine. Hosts behind pfSense 2 would be able to access hosts on the pfSense 1 LAN as long as pfSense 2 is outbound NATing the traffic, which removes the route asymmetry. But that obviously obscures the source IP.

                        Using a transport subnet between the two firewalls is a far more flexible setup and I would certainly recommend doing that if configuring a network where it's possible. But if you know you will never need to route the other way it will work without.

                        Steve

                        EveningStarNME 1 Reply Last reply Reply Quote 0
                        • EveningStarNME Offline
                          EveningStarNM @stephenw10
                          last edited by

                          @stephenw10 You are safe in assuming that, since that's what I said in my original post.

                          1 Reply Last reply Reply Quote 0
                          • stephenw10S Offline
                            stephenw10 Netgate Administrator
                            last edited by

                            Yeah, I originally read that as two separate things and the symptoms from the bad cable were exactly what I expect to see from an asymmetry issue throwing me into the weeds! 🙄

                            Anyway, moving on....

                            EveningStarNME 1 Reply Last reply Reply Quote 1
                            • EveningStarNME Offline
                              EveningStarNM @stephenw10
                              last edited by

                              @stephenw10 I forgot the first step: Always check the cables.

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