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

    Difference between Interface subnet and 192.168.2.0/24

    Scheduled Pinned Locked Moved Firewalling
    44 Posts 5 Posters 12.6k 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.
    • D
      doktornotor Banned
      last edited by

      @kejianshi:

      doktornotor - Currently I'm lost…
      I'd probably need a drawing of this to know what is going on.

      Basically something like this. But with client connected not from LAN, but via OVPN.

      1 Reply Last reply Reply Quote 0
      • K
        kejianshi
        last edited by

        I'll just watch and see how this goes…  Thanks.

        1 Reply Last reply Reply Quote 0
        • panzP
          panz
          last edited by

          @kejianshi:

          doktornotor - Currently I'm lost…

          I'd probably need a drawing of this to know what is going on.

          WAN (ISP) –-- pfsense ---- LAN

          So, pfsense has 2 physical interfaces: LAN & WAN. WAN has a public IP; LAN is 192.168.1.0/24 (pfsense is 192.168.1.1).

          Then I setup pfsense as client to AirVPN (a VPN service provider) so all my traffic is sent via VPN. Here's my NAT scheme:

          Then, I want to use my laptop with maximum security, so I setup a roadwarrior conf with pfsense acting as an OpenVPN server (tunnel is 192.168.2.0/24).

          Then, to prevent DNS leaks and LAN clients using Internet when AirVPN is down, I setup 2 floating rules:

          where MY_DNS_ADDRESSES is an alias to my favorite DNS servers (OpenNIC).

          Now I'm experimenting with firewall rules because, as far as I know, now my "exposed" interface is OpenVPN (because all my Internet traffic comes from there).

          pfSense 2.3.2-RELEASE-p1 (amd64)
          motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

          1 Reply Last reply Reply Quote 0
          • D
            doktornotor Banned
            last edited by

            Wasn't my question. Let me ask again:

            If you check the "Topology" checkbox, do both work (i.e., OPT3 subnet being the same as /24)?

            1 Reply Last reply Reply Quote 0
            • panzP
              panz
              last edited by

              @doktornotor:

              Wasn't my question. Let me ask again:

              If you check the "Topology" checkbox, do both work (i.e., OPT3 subnet being the same as /24)?

              There's only 1 (roadwarrior) client and it has 192.168.2.6 address.

              pfSense 2.3.2-RELEASE-p1 (amd64)
              motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

              1 Reply Last reply Reply Quote 0
              • D
                doktornotor Banned
                last edited by

                The question still remains the same. See the OpenVPN docs on net30 for the reason I'm asking.

                1 Reply Last reply Reply Quote 0
                • panzP
                  panz
                  last edited by

                  Yes, now checking that, the first rule works… so... why?

                  pfSense 2.3.2-RELEASE-p1 (amd64)
                  motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

                  1 Reply Last reply Reply Quote 0
                  • D
                    doktornotor Banned
                    last edited by

                    Well, because /30 is not /24  :P

                    net30 – Use a point-to-point topology, by allocating one /30 subnet per client.
                    subnet -- Use a subnet rather than a point-to-point topology by configuring the tun interface with a local IP address and subnet mask

                    Documentation. Also comparing the ifconfig output for both modes should be pretty much enlightening.

                    1 Reply Last reply Reply Quote 0
                    • K
                      kejianshi
                      last edited by

                      OK - So, your pfsense is a client to a vpn service and then your pfsense is also running an openvpn server to which your laptop/computer is a client while inside your own LAN?  Do I have this wrong?

                      1 Reply Last reply Reply Quote 0
                      • P
                        phil.davis
                        last edited by

                        Look in /tmp/rules.debug - down the end you will see the user rules generated from the Firewall Rules tabs. You will be able to see exactly what rules it generates for OPT3. I suspect it gets a different idea about OPT3 Subnet depending if it is set to topology or not. One way may treat it as a /30 and the other as the full tunnel network range.

                        As the Greek philosopher Isosceles used to say, "There are 3 sides to every triangle."
                        If I helped you, then help someone else - buy someone a gift from the INF catalog http://secure.inf.org/gifts/usd/

                        1 Reply Last reply Reply Quote 0
                        • panzP
                          panz
                          last edited by

                          Oh, yes, I understand that. But my question was: why does OPT subnet and 192.168.2.0/24 was not the same?

                          I understand this IF topology is net30, so is a peer-to-peer like connection.

                          But the previous scheme was ALL /24. Why this doesn't work?

                          pfSense 2.3.2-RELEASE-p1 (amd64)
                          motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

                          1 Reply Last reply Reply Quote 0
                          • D
                            doktornotor Banned
                            last edited by

                            @panz:

                            Oh, yes, I understand that. But my question was: why does OPT subnet and 192.168.2.0/24 was not the same?

                            Please, type ifconfig to console. For both modes. Compare the OPT3/ovpns? output.

                            1 Reply Last reply Reply Quote 0
                            • panzP
                              panz
                              last edited by

                              @kejianshi:

                              OK - So, your pfsense is a client to a vpn service and then your pfsense is also running an openvpn server to which your laptop/computer is a client while inside your own LAN?  Do I have this wrong?

                              laptop/computer is a client while I'm out (for eg. at a Strabucks coffee).

                              pfSense 2.3.2-RELEASE-p1 (amd64)
                              motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

                              1 Reply Last reply Reply Quote 0
                              • K
                                kejianshi
                                last edited by

                                OK - I see.

                                When you VPN into your pfsense from your laptop when you are out does all that traffic then go out over the VPN pfsense is client too?

                                1 Reply Last reply Reply Quote 0
                                • panzP
                                  panz
                                  last edited by

                                  @kejianshi:

                                  OK - I see.

                                  When you VPN into your pfsense from your laptop when you are out does all that traffic then go out over the VPN pfsense is client too?

                                  Yes.

                                  pfSense 2.3.2-RELEASE-p1 (amd64)
                                  motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

                                  1 Reply Last reply Reply Quote 0
                                  • K
                                    kejianshi
                                    last edited by

                                    haha - I see where this is going…  Good one.

                                    I take it AirVPN doesn't have a bandwidth usage cap?

                                    1 Reply Last reply Reply Quote 0
                                    • panzP
                                      panz
                                      last edited by

                                      @doktornotor:

                                      @panz:

                                      Oh, yes, I understand that. But my question was: why does OPT subnet and 192.168.2.0/24 was not the same?

                                      Please, type ifconfig to console. For both modes. Compare the OPT3/ovpns? output.

                                      with net30

                                      ovpns2: flags=8051 <up,pointopoint,running,multicast>metric 0 mtu 1500
                                      options=80000 <linkstate>inet6 fe80::a00:27ff:fe7f:875d%ovpns2 prefixlen 64 scopeid 0x8
                                      inet 192.168.2.1 –> 192.168.2.1 netmask 0xffffff00

                                      without inet30

                                      ovpns2: flags=8051 <up,pointopoint,running,multicast>metric 0 mtu 1500
                                      options=80000 <linkstate>inet6 fe80::a00:27ff:fe7f:875d%ovpns2 prefixlen 64 scopeid 0x8
                                      inet 192.168.2.1 --> 192.168.2.2 netmask 0xffffffff
                                      nd6 options=3 <performnud,accept_rtadv>Opened by PID 15822</performnud,accept_rtadv></linkstate></up,pointopoint,running,multicast></linkstate></up,pointopoint,running,multicast>

                                      pfSense 2.3.2-RELEASE-p1 (amd64)
                                      motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

                                      1 Reply Last reply Reply Quote 0
                                      • panzP
                                        panz
                                        last edited by

                                        @kejianshi:

                                        haha - I see where this is going…  Good one.

                                        I take it AirVPN doesn't have a bandwidth usage cap?

                                        no limitations as I know

                                        pfSense 2.3.2-RELEASE-p1 (amd64)
                                        motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

                                        1 Reply Last reply Reply Quote 0
                                        • D
                                          doktornotor Banned
                                          last edited by

                                          Yeah. So, see:

                                          netmask 0xffffffff = /32 (really just the OVPN IP itself, does not include any client, 192.168.2.6 certainly out)
                                          netmask 0xffffff00 = /24 (the configured subnet)

                                          1 Reply Last reply Reply Quote 0
                                          • panzP
                                            panz
                                            last edited by

                                            @doktornotor:

                                            Yeah. So, see:

                                            netmask 0xffffffff = /32 (really just the OVPN IP itself, does not include any client, 192.168.2.6 certainly out)
                                            netmask 0xffffff00 = /24 (the configured subnet)

                                            why  inet 192.168.2.1 –> 192.168.2.1

                                            pfSense 2.3.2-RELEASE-p1 (amd64)
                                            motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

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