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    DNS Resolver Split outgoing interface

    Scheduled Pinned Locked Moved DHCP and DNS
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    • DerelictD
      Derelict LAYER 8 Netgate @erasedhammer
      last edited by

      @erasedhammer said in DNS Resolver Split outgoing interface:

      Recently I setup up a domain controller which also acts as a DNS server, but I did not want clients using it as the primary dns server,

      Why would one invest in a domain controller but not have their clients use it as the source of information for the domain?

      Genuinely curious.

      Chattanooga, Tennessee, USA
      A comprehensive network diagram is worth 10,000 words and 15 conference calls.
      DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
      Do Not Chat For Help! NO_WAN_EGRESS(TM)

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      • E
        erasedhammer @Derelict
        last edited by

        @derelict
        The domain override exists for clients to ask the domain controller domain related DNS queries. What I didn't want is the domain controller handling internet DNS queries.

        But to directly answer your question, the domain controller is virtualized on a less than reliable server right now. It isn't that critical right now, nothing important relies on it at this point, just a couple of VDIs.

        johnpozJ 1 Reply Last reply Reply Quote 0
        • johnpozJ
          johnpoz LAYER 8 Global Moderator @erasedhammer
          last edited by

          Lets see your gateway and routing table.. The only way pfsense would talk to some gateway from its lan IP, if the gateway is attached to the lan network.

          This is how any router would work. Its not something special to pfsense.

          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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          • E
            erasedhammer @johnpoz
            last edited by

            @johnpoz
            Heres the gateway list:
            gateway.png

            I don't have any internet static routes though, so everything gets sent to that default gateway.

            johnpozJ 1 Reply Last reply Reply Quote 0
            • johnpozJ
              johnpoz LAYER 8 Global Moderator @erasedhammer
              last edited by

              But lets see the routing table.. Pfsense shouldn't use the lan IP when it wants to talk to 172.20.0.1

              It shouldn't be able to.. Makes no sense to use that IP when trying to talk to something that is not on that 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 24.11 | Lab VMs 2.8, 24.11

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                erasedhammer @johnpoz
                last edited by

                @johnpoz

                I don't see anything saying to use one of the lan interfaces to go to the internet

                routetable.png

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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator @erasedhammer
                  last edited by

                  Maybe @Derelict has some idea.. I am drawing a blank to how/why it could/would 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
                  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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                  • V
                    viniciusmerlim
                    last edited by

                    Have you set the gateway for your server interface? I think you will need to create static routes and set these dns policies in DNS resolver. You will also need to allow this traffic in the rules and put the SERVERS gateway in advanced configuration of these rules for users to use this weird configuration.

                    What a tricky scenario.

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                    • E
                      erasedhammer @viniciusmerlim
                      last edited by

                      @viniciusmerlim

                      What do you mean by gateway for the server interface? It is a gateway in itself.
                      And by static routes, do you mean static routes inside the dns resolver itself? I am unfamiliar with how to do that.

                      Is it a weird configuration? Domain overrides can be used for more than my weird domain controller setup.
                      I think if the domain override could work without selecting additional outgoing interfaces, I wouldn't be seeing this behavior.

                      DerelictD 1 Reply Last reply Reply Quote 0
                      • DerelictD
                        Derelict LAYER 8 Netgate @erasedhammer
                        last edited by

                        @erasedhammer What have you selected as the outgoing interfaces in DNS Resolver/unbound?

                        No, you cannot source a connection for a specific domain from a specific source address. This is something dnsmasq (DNS Forwarder) could do but unbound cannot, unfortunately.

                        Chattanooga, Tennessee, USA
                        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                        Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                        • E
                          erasedhammer @Derelict
                          last edited by

                          @derelict

                          splitdns-resolveroutgoing.png

                          DerelictD 1 Reply Last reply Reply Quote 0
                          • DerelictD
                            Derelict LAYER 8 Netgate @erasedhammer
                            last edited by

                            @erasedhammer So it is doing exactly what you told it to do? Source queries from both addresses?

                            Chattanooga, Tennessee, USA
                            A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                            DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                            Do Not Chat For Help! NO_WAN_EGRESS(TM)

                            E 1 Reply Last reply Reply Quote 0
                            • E
                              erasedhammer @Derelict
                              last edited by

                              @derelict

                              Correct, but the domain override and telling it to use an internal DNS server does not work without selecting the servers interface as outgoing.
                              I guess that is the root of my question, why can't the domain override work without the interface being selected in the outgoing interfaces list.

                              DerelictD 1 Reply Last reply Reply Quote 0
                              • DerelictD
                                Derelict LAYER 8 Netgate @erasedhammer
                                last edited by

                                @erasedhammer Because unbound doesn't have that functionality.

                                Chattanooga, Tennessee, USA
                                A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                                DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                                Do Not Chat For Help! NO_WAN_EGRESS(TM)

                                1 Reply Last reply Reply Quote 0
                                • DerelictD
                                  Derelict LAYER 8 Netgate
                                  last edited by

                                  @erasedhammer If you set the outgoing interface to All, what happens?

                                  That should move the source address selection back to FreeBSD which should select the "closest" interface to the destination address.

                                  Chattanooga, Tennessee, USA
                                  A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                                  DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                                  Do Not Chat For Help! NO_WAN_EGRESS(TM)

                                  E 1 Reply Last reply Reply Quote 1
                                  • E
                                    erasedhammer @Derelict
                                    last edited by

                                    @derelict

                                    Seems to be working. Domain override is working and Im not seeing any other interfaces going to the internet.

                                    I guess I overthought the implementation, thanks!

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