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    How to separate 3 LANs on a quad-port NIC so they have no access to the other networks?

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    • F Offline
      FireQ
      last edited by

      I am new to pfSense and recently installed it on the and old desktop with the intention of having 3 networks each of which are separate and not able to see the devices on the other networks:

      • Lenovo Thinkcentre M series, 3.0Mhz process, 10gb ddr3 RAM

      I added a quad port NIC ( HP NC364T Network Card ) and have setup 1 as the WAN port and 3 separate LAN ports:
      LAN1: Home network
      LAN2: IOT network
      LAN3: Guest network

      All 3 LANs connect to separate downstream WIFI routers and I have cable running through the home to connect them to pfSense. The setup is

      LAN1: connects to Lan port of WiFi router with DHCP disabled. PfSense provides the DHCP
      LAN2: connects to WAN port of WIFI router with DHCP enabled
      LAN3: connects to WAN port of WIFI router with DHCP enabled

      I have setup two Block rules on the Firewall for both LAN2 and LAN3 not to (a) have access to LAN1 devices and (b) not have access to the firewall web page.

      All works fine but for some reason both LAN2 and LAN3 can access pfSense web page on 192.168.0.1 even though their subnets are totally different.

      How can correct this and ensure that all 3 LANs remain separate? Any help would be appreciated!

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      • V Offline
        viragomann @FireQ
        last edited by

        @fireq said in How to separate 3 LANs on a quad-port NIC so they have no access to the other networks?:

        All works fine but for some reason both LAN2 and LAN3 can access pfSense web page on 192.168.0.1 even though their subnets are totally different.

        Don't know, which interface this IP is assigned to, you didn't mention.

        However, assuming you're using RFC1918 subnets only internally, just create an alias (Firewall > Aliases) of type IP, networks and add all RFC1918 network ranges to it.
        Then add a block rule to the top of each interface rule set with this alias as destination and protocol = any.
        So that will block any access to RFC1918 IPs.

        If you use pfSense for DNS resolution you have to allow this access by a separate rule. So add a pass rule allowing DNS access to "this firewall" and put it above the block rule.

        You may also handling the desired behavior with floating rules if you are familiar with it.

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        • johnpozJ Online
          johnpoz LAYER 8 Global Moderator @FireQ
          last edited by

          @fireq said in How to separate 3 LANs on a quad-port NIC so they have no access to the other networks?:

          LAN2: connects to WAN port of WIFI router with DHCP enabled
          LAN3: connects to WAN port of WIFI router with DHCP enabled

          Why would you do that?

          An intelligent man is sometimes forced to be drunk to spend time with his fools
          If you get confused: Listen to the Music Play
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          • F Offline
            FireQ @viragomann
            last edited by

            @viragomann Thanks for your quick reply. The 192.168.0.1 is on the LAN1 So I setup the following Floating rule:

            Screen Shot 2020-12-21 at 12.08.53 PM.png

            Screen Shot 2020-12-21 at 12.09.10 PM.png

            and for the separate LANs have the following rules:
            Screen Shot 2020-12-21 at 12.09.29 PM.png

            Do these seem right?

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            • F Offline
              FireQ @johnpoz
              last edited by

              @johnpoz I thought that would provide an extra layer to keep the networks separate and I don't care too much about the bandwidth on the IOT and Guest networks. Would it be better to just disable DHCP on all downstream routers?

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              • johnpozJ Online
                johnpoz LAYER 8 Global Moderator @FireQ
                last edited by johnpoz

                Yeah it gives you more insight and control into what is on your network, and what they are doing.

                Why would you hide stuff behind another nat on your own network?

                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 25.07 | Lab VMs 2.8, 25.07

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                • F Offline
                  FireQ @johnpoz
                  last edited by

                  @johnpoz I don't want guests or the IOT devices with weak security to be able to access my main LAN or the firewall.

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                  • ? Offline
                    A Former User
                    last edited by A Former User

                    Just create block rules on the network you want to isolate.

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                    • johnpozJ Online
                      johnpoz LAYER 8 Global Moderator @FireQ
                      last edited by johnpoz

                      @fireq

                      What does that have to do with downstream nat.. Unless you have the rules inplace on your firewall to stop access they would still be able to access your lan.. Unless you were using the same network as what is behind your routers?

                      Not sure what good removing your insight and control of stuff on your network - if the goal is blocking access.. Which is as simple 1 firewall rule..

                      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 25.07 | Lab VMs 2.8, 25.07

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                      • V Offline
                        viragomann @FireQ
                        last edited by

                        @fireq
                        It may be more reliable to use the preset "this firewall" alias for blocking access to pfSense itselft then creating your own alias.

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                        • F Offline
                          FireQ @johnpoz
                          last edited by

                          @johnpoz thanks john. am still learning so obviously making mistakes but the feedback is helpful

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                          • F Offline
                            FireQ @viragomann
                            last edited by

                            @viragomann thanks, I tried that first but still had access to the gui so changed to the specific IP.

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                            • johnpozJ Online
                              johnpoz LAYER 8 Global Moderator @FireQ
                              last edited by

                              @fireq said in How to separate 3 LANs on a quad-port NIC so they have no access to the other networks?:

                              I tried that first but still had access to the gui

                              Keep in mind that just because you create a block rule doesn't mean there isn't an existing state that is allowing the traffic.

                              When you go to block something - you need to make sure there is no existing state that is allowing.

                              The "this firewall" is the best way to block access to the firewall for vlans you don't want to be able to access stuff on the firewall you don't want.. because it also includes the wan IP which is quite often public. So would not be included in any rfc1918 alias you use..

                              Here is a example set of rules for a locked down vlan..

                              rules.png

                              Can be modified for your wants/needs. It allows this vlan to ping pfsense IP on that vlan - for connectivity testing. It allows access to dns and ntp.. But then all other access to any other vlan or any firewall IP is rejected. Rejected can help with letting the client know - you ain't getting there... So no need to keep trying via retrans, etc. This can be helpful on local networks - would never do on wan.

                              Then it allows everything else, ie the internet.

                              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 25.07 | Lab VMs 2.8, 25.07

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                              • F Offline
                                FireQ @johnpoz
                                last edited by

                                @johnpoz great! thanks for the explanation. will use that example and modify for my setup.

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