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    DNS leaks

    Scheduled Pinned Locked Moved DHCP and DNS
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    • panzP
      panz
      last edited by

      pfsense leaks. a lot.

      General setup –> DNS: everything you put here is leaked, even if you're using a VPN provider connection.

      Just for comparison, a simple router/firewall with DD-WRT or Tomato doesn't leak any DNS info, and shows only the DNS server of your VPN provider. Just play with

      https://www.dnsleaktest.com/

      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.

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      • D
        doktornotor Banned
        last edited by

        @panz:

        Just play with https://www.dnsleaktest.com/

        Awesome. It shows the IP of my pfsense boxes running unbound. Oh noes, I am leaked!  ::) ::) ::)

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        • panzP
          panz
          last edited by

          As usual, I didn't say it in the right manner  ;D

          I mean, if you set for example 3 DNS servers in System General setup and you're using pfsense as OpenVPN client to a VPN provider, the pfsense box doesn't pass the test indicated above.

          I suppose that pfsense should only show the DNS in use (aka the DNS of the VPN provider) and not LIST all the system's DNSs.

          Am I missing something?

          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.

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          • panzP
            panz
            last edited by

            @doktornotor:

            Awesome. It shows the IP of my pfsense boxes running unbound. Oh noes, I am leaked!  ::) ::) ::)

            Just finished 4 days of testing. Involved configurations are: DD-WRT, Tomato (Toastman ver.), and D-Link 2640 firmware series (basically, it's Linux).

            All of these - in the DNSleak or IPLeak tests - show only the DNS pushed by the server (for AirVPN UDP settings the dns is 10.4.0.1).

            BTW Windows leaks (this is not bad news, we know that rubb…) but there is a workaround (and a clever one, I think):

            https://airvpn.org/topic/9798-windows-7-8-windows-firewall-prevent-leaks-thanks-to-omniferum/

            It requires a bit of knowledge, but it WORKS!  ;)

            Now, how can I get the same result with pfsense? I've just tried all the possible configurations (allowed by the GUI), but I didn't achieve the desired results.

            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.

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            • D
              doktornotor Banned
              last edited by

              There is no DNS "pushed" by server to pfSense OpenVPN client. Add OpenVPN foreign_option support. Apparently noone produced anything so far.

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              • panzP
                panz
                last edited by

                So, it's impossible to honor the request set by redirect gateway def-1 because, if the "client" pfsense queries more than 1 DNS, we have not all traffic sent through the tunnel (for example Tomato does that for DNS; now I'm going to look at the source scripts to learn how it works), but I can't see how that can be a "feature"  :-[

                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.

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                • E
                  eri--
                  last edited by

                  By default all dns configured is queried in parallell to reduce delays.

                  The setting used in pfSense is

                  –all-servers
                  By default, when dnsmasq has more than one upstream server available, it will send queries to just one server. Setting this flag forces dnsmasq to send all queries to all available servers. The reply from the server which answers first will be returned to the original requester.

                  To disable it for now you can put a feature request in redmine and edit /etc/inc/services.inc  and remove the option manually.

                  1738                $cmd = "/usr/local/sbin/dnsmasq –all-servers {$dns_rebind} {$args}";

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                  • D
                    doktornotor Banned
                    last edited by

                    Well that won't exactly help I'm afraid since you won't be using the pushed DNS servers regardless. You do not want to use any of the preconfigured DNS servers for this.

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                    • K
                      kejianshi
                      last edited by

                      That DNS leak test thing doesn't show crap for me…

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

                        @kejianshi:

                        That DNS leak test thing doesn't show crap for me…

                        With pfsense acting as OpenVPN client to a VPN provider?

                        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.

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                        • K
                          kejianshi
                          last edited by

                          No - With clients directly on pfsense or using pfsense as openvpn server.
                          All that page is doing is looking at where you get your DNS, so far as I can tell.

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                          • panzP
                            panz
                            last edited by

                            @kejianshi:

                            No - With clients directly on pfsense or using pfsense as openvpn server.
                            All that page is doing is looking at where you get your DNS, so far as I can tell.

                            I have no problems at all with your configuration. No leaks. My conf is different: pfsense is acting as OpenVPN client to a VPN service provider, so I'd like to use ONLY provider's DNS server.

                            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.

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                            • K
                              kejianshi
                              last edited by

                              If they have a couple DNS servers, that should be no problem.  If they aren't providing DNS servers, you are out of luck.  You could also run your own DNS server?

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                              • panzP
                                panz
                                last edited by

                                @kejianshi:

                                If they have a couple DNS servers, that should be no problem.  If they aren't providing DNS servers, you are out of luck.  You could also run your own DNS server?

                                They definitely have their own DNS servers! The matter seems to be that pfsense is not accepting all the pushed configs (OpenVPN foreign_option).

                                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.

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                                • K
                                  kejianshi
                                  last edited by

                                  Is it possible you can get their server IPs from them and enter them manually?

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                                  • D
                                    doktornotor Banned
                                    last edited by

                                    @kejianshi:

                                    Is it possible you can get their server IPs from them and enter them manually?

                                    Not really an option for most people, you are stuck with no DNS at all once the client gets disconnected. The foreign options support is pretty much required to work not just on Windows. Usually done via up/down scripts and resolvconf package on Linux distros.

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                                    • K
                                      kejianshi
                                      last edited by

                                      Thats good - Then when the vpn is down, the internet won't work, which is how I like it when I want a full time vpn running.
                                      Thats exactly the way my phone behaves.  You either have vpn or you have nothing.

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                                      • H
                                        humungus
                                        last edited by

                                        Its been several years, is this still the case? Followed this tutorial below and ended up in the same boat with VPN provided DNS servers not being picked up by pfsense/openvpn client. Would it be possible to add an additional argument to make this work? Thanks in advance

                                        https://forum.pfsense.org/index.php?topic=76015.0

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                                        • G
                                          gjaltemba
                                          last edited by

                                          Wow. Resurrecting a thread from 2013? OK, I'll bite.

                                          When I run dnsleaktest, the result is my vpn server ip for wan and dns.

                                          Make sure dns resolver is running.
                                          Uncheck forwarding mode.
                                          Select the vpn interface in Outgoing Network Interfaces.
                                          Do not enter dns servers in General settings.

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                                          • H
                                            humungus
                                            last edited by

                                            @gjaltemba:

                                            Wow. Resurrecting a thread from 2013?

                                            Well I ran into the same problem lol.

                                            @gjaltemba:

                                            When I run dnsleaktest, the result is my vpn server ip for wan and dns.

                                            Make sure dns resolver is running.
                                            Uncheck forwarding mode.
                                            Select the vpn interface in Outgoing Network Interfaces.
                                            Do not enter dns servers in General settings.

                                            That does the trick and gives me the ability to use my vpn dns for my lan traffic. Kind of something I didn't even know I wanted. Thanks!!

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