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    Allow LAN to LAN, not routing

    Scheduled Pinned Locked Moved General pfSense Questions
    37 Posts 6 Posters 3.3k Views
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    • V
      viragomann
      last edited by

      The devices in LAN 2 will send responses to their default gateway, since they don't have a route to LAN 1.
      So either add a route to each device (properly per DHCP) or set up a transit network between the two routers (gateways) and set up static route on both for the networks behind them as @johnpoz has illustrated here: https://forum.netgate.com/topic/145513/firewall-routing-problem/7

      A dirty workaround here is to add an outbound NAT rule to the LAN 2 interface which translates source addresses in outgoing packets into the interface address. If this is practicable for you depends on your needs.

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        @lewis said in Allow LAN to LAN, not routing:

        that has its own gateway.

        Yeah that is going to be problem.. When you say you added another IP to a device... This sounds like your running 2 different L3 networks on the same L2 network... This is not optimal..

        Could you draw up how you have everything connected and we can work out how to do what you want to do.

        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

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        • KOMK
          KOM
          last edited by KOM

          That won't work. Virtual IPs are used so that pfSense can pretend to be another host. What you ended up with was pfSense spoofing that IP address, so it wouldn't work like your real NFS server other then pinging it. Also, I'm not sure how you're expecting to get traffic from one network to another without routing it, regardless of whether they're LANs, WANs or whatever.

          Add a static route via System - Routing - Static Routes by specifying the destination network and its gateway.

          (Bah, I didn't notice John and viragomann slipping in first...)

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by johnpoz

            Sure could do a source nat if required - but I want to make sure he is just not running both L3 on the same L2... That is never a good way to do anything.

            But sure if his other network is actually different L2 then we could source nat if need be.

            Prob better to put this other gateway on a transit connected to pfsense and route/firewall everything that way.

            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

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            • L
              lewis
              last edited by lewis

              lan-to-neighbor-lan.png

              Very simplistic image but we have our own LAN, 10.0.0.1.
              We have a neighbor in the data center that is going to share some data with us.
              They have their own LAN at 10.0.1.1 for example and they have their our gateway on that LAN of course.
              I don't want to route or be the gateway for that LAN, I just need to reach the NFS storage device on their LAN.

              Of course, I have no control over their LAN or what they use or how they use it. I only have the possibility of using this storage if I can reach it. The two servers I show would want to mount that NFS share.

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              • KOMK
                KOM
                last edited by

                I don't want to route...

                WHY NOT?

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                • V
                  viragomann
                  last edited by viragomann

                  @lewis said in Allow LAN to LAN, not routing:

                  I don't want to route

                  You have a routing issue...

                  So you have only to add a static route for your LAN 10.0.0.0/24 pointing to the pfSense IP in 10.0.1.0/?? on the NFS storage. That's all you need.

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                  • L
                    lewis
                    last edited by

                    I don't want to route meant I cannot route their network, we aren't their gateway. Sorry that wasn't clear.
                    I basically just need LAN to LAN access from our own 10.0.0.1 LAN to devices on their 10.0.1.1 LAN network.

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                    • KOMK
                      KOM
                      last edited by

                      You can most certainly route to their network, and if they're onboard with sharing data with you then surely they can add a static route on their end for the 5 second it would take?

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                      • L
                        lewis
                        last edited by

                        Yes, our traffic is allowed, it's me that is not sure what to do on our end as I don't want to break something.

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

                          You need a working communication between the NFS storage and your LAN devices as you stated above. So you need a static route for your LAN on the device in the other LAN. The default route can still stay as it is and upstream traffic from the NFS may go out the neighbours gateway.

                          As I mentioned above, you may also do a workaround with NAT.
                          To do so go to Firewall > NAT > outbound. Switch into the hybrid mode, save and add a new rule:
                          interface: LAN2
                          Source: your LAN network or an alias with the two considered servers in your LAN
                          Translation address: interface address

                          If you want you may also restrict protocol and port.

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                          • KOMK
                            KOM
                            last edited by

                            Adding a static route to them won't break anything unless you're really, really good.

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                            • L
                              lewis
                              last edited by

                              So, not doubting anything since I'm already at a point where I'm not knowledgeable enough and had to ask but, I had added a virtual (alias) IP with the IP of the storage device. I wanted to point out that I can already ping the storage device on their LAN. I just can't mount it and get RPC errors.

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                              • KOMK
                                KOM
                                last edited by

                                But you're not really pinging that NFS server, are you? You're pinging pfSense which is pretending to be that IP address. That's what a Virtual IP - IP Alias is. I explained all this in my first post.

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                                • V
                                  viragomann @lewis
                                  last edited by viragomann

                                  @lewis said in Allow LAN to LAN, not routing:

                                  I had added a virtual (alias) IP with the IP of the storage device. I wanted to point out that I can already ping the storage device on their LAN.

                                  The ping will not reach the device in the other network if the destination IP is on your own router!

                                  Edit: Okay, KOM has the same idea and was faster. ☺

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                                  • L
                                    lewis
                                    last edited by

                                    Please guys, I appreciate the help, don't get impatient with me. I know you explained but this is not my network to break so am counting on you guys to help me do the right thing.

                                    It makes sense that I can ping the IP if I added it on the local router. I had not thought about that.

                                    Changing to hybrid won't break anything that is running now? I mean, will it require a reboot or something? Pfsense is always highly reliable and never need to reboot it but I'm asking since we are changing a 'mode'.

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                                    • V
                                      viragomann
                                      last edited by

                                      Changing the outbound NAT mode from automatic to hybrid does nothing. The automatically added rules are still in place and you're able to add manual rules.

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                                      • L
                                        lewis
                                        last edited by

                                        NAT > outbound. Switch into the hybrid mode

                                        Done.

                                        save and add a new rule:
                                        interface: LAN2

                                        The above is not clear to me. I've not create d a new interface and don't see one. I only see the usual WAN and LAN in Interface so I'm missing something before I can add rules next.

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                                        • V
                                          viragomann
                                          last edited by

                                          So the neighbours LAN is really not on an separate interface? It's connected directly to your LAN as John assumed?

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                                          • L
                                            lewis
                                            last edited by lewis

                                            The pfsense box has two interfaces only, WAN and LAN.
                                            Our LAN subnet is 10.0.0.1/24.
                                            On the LAN side, there are many other segments and I need to connect to a neighbors LAN and a storage device at 10.100.100.12.
                                            They too route their own 10.100.100.1/24 subnet, have their own DHCP service, etc so I don't want to break anything on either subnet.

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