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    Enable Static ARP entries not working correctly

    Scheduled Pinned Locked Moved DHCP and DNS
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    • M
      mateusz
      last edited by

      I noticed the same problem, I have these options in DHCP server:
      Deny Unknown Clients: Allow known clients from only this interface
      Static ARP: checked Enable Static ARP entries
      device is not on the list of DHCP Static Mappings
      Results:
      pfSense CE 2.6: device with manually set static IP address = no connection to pfSense and Internet
      pfSense CE 2.7.2: device with manually set static IP address = there is a connection to pfSense and Internet

      I tested this on fresh, clean installations of pfSense CE, 2.6 and 2.7.2, only above settings were changed.

      My question is - which behavior is correct?

      GertjanG 1 Reply Last reply Reply Quote 0
      • GertjanG
        Gertjan @mateusz
        last edited by

        @mateusz said in Enable Static ARP entries not working correctly:

        Deny Unknown Clients: Allow known clients from only this interface
        Static ARP: checked Enable Static ARP entries
        device is not on the list of DHCP Static Mappings

        So the device won't get a lease.
        That is : shouldn't get a lease.

        But, be aware, I've never played with this option :

        6581123e-a4b8-4cd7-bfc0-af17f6bc8f67-image.png

        No "help me" PM's please. Use the forum, the community will thank you.
        Edit : and where are the logs ??

        M 1 Reply Last reply Reply Quote 0
        • M
          mateusz @Gertjan
          last edited by

          @Gertjan
          Yes, device not getting a lease in both versions, 2.6 and 2.7.2, but in case I set static IP address on this device there is a different behaviour depending on pfSense version. With version 2.6 device cannot communicate with pfSense and therefore Internet. With 2.7.2 device can communicate with pfSense/Internet.

          P GertjanG 2 Replies Last reply Reply Quote 0
          • P
            pcready.cl @mateusz
            last edited by

            @mateusz said in Enable Static ARP entries not working correctly:

            @Gertjan
            Yes, device not getting a lease in both versions, 2.6 and 2.7.2, but in case I set static IP address on this device there is a different behaviour depending on pfSense version. With version 2.6 device cannot communicate with pfSense and therefore Internet. With 2.7.2 device can communicate with pfSense/Internet.

            Same here, with pfSense+ 24.03-RELEASE (amd64) device can communicate with pfSense/Internet.

            1 Reply Last reply Reply Quote 0
            • GertjanG
              Gertjan @mateusz
              last edited by

              @mateusz said in Enable Static ARP entries not working correctly:

              but in case I set static IP address on this device

              In that case the pfSense DHCP server isn't solicited.
              If all devices on your LAN have static IP assignments (IP, network,DNS, gateway), you could even shut down the pfSense DHCP server on that LAN.

              No "help me" PM's please. Use the forum, the community will thank you.
              Edit : and where are the logs ??

              M 1 Reply Last reply Reply Quote 0
              • M
                mateusz @Gertjan
                last edited by

                @Gertjan
                Enabled/disabled DHCP server is not the point. I can deactivate DHCP server but behaviour is the same - in pfSense 2.6 device with static IP address can't communicate with pfSense/Internet, in pfSense 2.7.2 it can. I believe Enable Static ARP entries option works different in both versions. Based on description I thought that only devices from the list of DHCP Static Mappings will be able to talk with pfSense. This works that way in version 2.6 but not in version 2.7.2.

                Description from GUI:
                Enable Static ARP entries
                Restricts communication with the firewall to only hosts listed in static mappings containing both IP addresses and MAC addresses. No other hosts will be able to communicate with the firewall on this interface. This behavior is enforced even when DHCP server is disabled.

                Description from Netgate documentation:
                Static ARP:
                This checkbox works similar to denying unknown MAC addresses from obtaining leases, but takes it a step further in that it also restricts any unknown MAC address from communicating with this firewall. This stops would-be abusers from hardcoding an unused address on this subnet, circumventing DHCP restrictions.

                GertjanG 1 Reply Last reply Reply Quote 0
                • GertjanG
                  Gertjan @mateusz
                  last edited by

                  @mateusz said in Enable Static ARP entries not working correctly:

                  in pfSense 2.6 device with static IP address can't communicate with pfSense/Internet

                  When you install a pfSense with default settings (you change nothing except the password), from the very first beta version 0.9, more then a decade ago, up to latest 2.7.2 (or 24.03) : any device connected to the LAN port can connect to pfSense, and the Internet, if the WAN is also connected.

                  Remember : pfSense behaves as any router you can buy out there.

                  Ok, true, if you have a PPPOE connection, you need to create a pppoe setup on your WAN interface.

                  As my pfSense uses 192.168.1.1/24 on its LAN, and the DHCP server is by default activated on LAN, I can connect my PC to this LAN port, and I have access. This behavior never changed.

                  If your WAN is "special" or "different", tell us about it.

                  Things like "Enable Static ARP entries" : I never had to deal with that.
                  "DHCP Static Mappings" : I use these all the time. And that's why I use ISC, and not KEA (I use a 24.03).

                  @mateusz said in Enable Static ARP entries not working correctly:

                  denying unknown MAC addresses from obtaining leases

                  I never had to deal with "deny unknown MAC addresses" as the kids at home are over 8 years old so they know how to bypass that (no, I'm not joking).

                  No "help me" PM's please. Use the forum, the community will thank you.
                  Edit : and where are the logs ??

                  M 1 Reply Last reply Reply Quote 0
                  • M
                    mateusz @Gertjan
                    last edited by mateusz

                    @Gertjan
                    I checked once again my configurations on 2.6 and 2.7.2 versions. They are test machines and both have default settings with changes made only in DHCP server service:

                    Deny Unknown Clients: Allow known clients from only this interface
                    Static ARP: checked Enable Static ARP entries
                    device is not on the list of DHCP Static Mappings

                    I think there is a misunderstanding and I will try to describe my configuration and my question better.

                    In both 2.6 and 2.7.2 versions with default settings I connect my test laptop directly to LAN port, also I have WAN with DHCP and as you said I can connect to pfSense and have Internet access.

                    But when I change settings in DHCP service to mentioned above, pfSense behaves differently depending on its version.

                    In 2.6 test laptop (with static IP address) connected to LAN port cannot access pfSense and therefore Internet.
                    But in 2.7.2 the same test laptop (with static IP address) connected to LAN port can access pfSense and Internet.

                    Enabled/disabled DHCP server does not change this behavior.

                    I know bypassing of "deny unknown MAC addresses" is easy but I am curious why pfSense in different versions behaves differently with the same settings.

                    GertjanG 1 Reply Last reply Reply Quote 0
                    • GertjanG
                      Gertjan @mateusz
                      last edited by

                      @mateusz

                      DHCP : ISC or Kea ?

                      No "help me" PM's please. Use the forum, the community will thank you.
                      Edit : and where are the logs ??

                      M 1 Reply Last reply Reply Quote 0
                      • M
                        mateusz @Gertjan
                        last edited by

                        @Gertjan
                        Still ISC.

                        1 Reply Last reply Reply Quote 0
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