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

    pfSense as subrouter, track interface and routing problems

    Scheduled Pinned Locked Moved IPv6
    25 Posts 2 Posters 3.3k 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.
    • S
      Spaylia @Spaylia
      last edited by Spaylia

      @JKnott I managed to make it work temporarily, I could ping internet from the LAN interface, but my clients still couldn't. Oddly enough there was no addresses on the LAN interface.

      When I rebooted, LAN address came back and ping wasn't working anymore. I tried both "track interface" and static IP.

      JKnottJ 1 Reply Last reply Reply Quote 0
      • JKnottJ
        JKnott @Spaylia
        last edited by JKnott

        @Spaylia

        Maybe you should start over from scratch. You might have made so many changes starting over may be easier. Start with the config I provided for my ISP.

        PfSense running on Qotom mini PC
        i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
        UniFi AC-Lite access point

        I haven't lost my mind. It's around here...somewhere...

        1 Reply Last reply Reply Quote 0
        • S
          Spaylia
          last edited by Spaylia

          @JKnott do I need to add a route or gateway in the first router?

          With IPv4, the router keeps a table of the translated address and port and sends the response back where it comes from, to be translated by the second router.

          I'm not sure about IPv6. Does the router know where it comes from if it comes from another subnet (behind router 2)?

          JKnottJ 1 Reply Last reply Reply Quote 0
          • JKnottJ
            JKnott @Spaylia
            last edited by

            @Spaylia

            With IPv6, the default route is set automagically. With SLAAC, it's provided by the router advertisements. You can see this, if you capture with Packet Capture, filtering on icmp6.

            PfSense running on Qotom mini PC
            i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
            UniFi AC-Lite access point

            I haven't lost my mind. It's around here...somewhere...

            S 1 Reply Last reply Reply Quote 0
            • S
              Spaylia @JKnott
              last edited by Spaylia

              @JKnott I'm not asking about the default route, but a downstream route for Router 1, to send the responses to Router 2

              When a client requests something, it goes:
              Client -> router 2 -> router 1 -> internet

              When the server answers
              internet -> router 1 -> router 2 -> client

              Do I need a route from router 1 to router 2 so the answer can be router back?

              JKnottJ 1 Reply Last reply Reply Quote 0
              • JKnottJ
                JKnott @Spaylia
                last edited by

                @Spaylia

                It will know the route to the next router, but not the network behind it. So, you'll have to configure the route for that network.

                PfSense running on Qotom mini PC
                i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                UniFi AC-Lite access point

                I haven't lost my mind. It's around here...somewhere...

                S 1 Reply Last reply Reply Quote 0
                • S
                  Spaylia @JKnott
                  last edited by Spaylia

                  @JKnott Alright, I got it to work, it was a problem with the configuration of R1, after looking at the routes in R1, I noticed it wasn't delegating the prefix properly.

                  Although devices (mostly debian hosts) under R1 are still advertised with R2 (pfsense) WAN as a default route. Would you know if there's a way to see who advertised a route on debian?

                  JKnottJ 1 Reply Last reply Reply Quote 0
                  • JKnottJ
                    JKnott @Spaylia
                    last edited by

                    @Spaylia

                    Do a Packet Capture, filtering on icmp6. You will, after a few minutes, have some router advertisements, which provide the route. Examine the source MAC address to see where it's coming from.

                    PfSense running on Qotom mini PC
                    i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                    UniFi AC-Lite access point

                    I haven't lost my mind. It's around here...somewhere...

                    S 1 Reply Last reply Reply Quote 0
                    • S
                      Spaylia @JKnott
                      last edited by

                      @JKnott Makes sense, thank you!

                      S 1 Reply Last reply Reply Quote 0
                      • S
                        Spaylia @Spaylia
                        last edited by

                        @JKnott well, it comes from pfSense WAN somehow

                        2023-12-02 23:35:52.560376 xx:xx:xx:xx:xx:5d (oui Unknown) > 33:33:00:00:00:01 (oui Unknown), ethertype IPv6 (0x86dd), length 198: fe80::xxxx:xxff:fexx:xx5d > ip6-allnodes: ICMP6, router advertisement, length 144

                        5d is the MAC address/link local address of the WAN interface
                        318d8a30-7da4-4784-a9b7-5f136cdbc34f-image.png

                        JKnottJ 1 Reply Last reply Reply Quote 0
                        • JKnottJ
                          JKnott @Spaylia
                          last edited by

                          @Spaylia

                          That's not right. It can only be the LAN interface.

                          PfSense running on Qotom mini PC
                          i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                          UniFi AC-Lite access point

                          I haven't lost my mind. It's around here...somewhere...

                          S 1 Reply Last reply Reply Quote 0
                          • S
                            Spaylia @JKnott
                            last edited by

                            @JKnott Since I can't add a deny rule for router advertisement on WAN (I guess hidden rules come before to allow it), I added an ip6tables rule to deny icmpv6 type 134 (RA) from fe80::xxxx:xxff:fexx:xx5d to all clients in the WAN of pfsense, and I don't get the route anymore.

                            JKnottJ 1 Reply Last reply Reply Quote 0
                            • JKnottJ
                              JKnott @Spaylia
                              last edited by

                              @Spaylia

                              Well, I don't know what to say. It's a really strange system you have there. The MAC address comes from the NIC, not pfSense. So, if you're seeing the MAC, that is the 48 bit hardware address, on the LAN side, there must be some other path involved. This is why I asked you to provide the Packet Capture file, so that I can examine it in Wireshark.

                              PfSense running on Qotom mini PC
                              i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                              UniFi AC-Lite access point

                              I haven't lost my mind. It's around here...somewhere...

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