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    Additional DC not functioning if the Primary DC is down !!

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    • DenisKelleyD
      DenisKelley
      last edited by

      Best explanation regarding this that I've seen. See Jay's response:
      http://community.spiceworks.com/topic/post/4301599

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      • IT-ADMINI
        IT-ADMIN
        last edited by

        let us suppose that DC2 is offline and cannot see DC1 (which is the main reason i want to make DC2 for high availability) how DNS setting make any difference ??

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        • DashrenderD
          Dashrender
          last edited by

          Yes.

          Let's assume DC2 is offline, but you want to see if you can run ADUC on DC2. When you run ADUC it uses DNS to try to open and failes.

          But if you put in 127.0.0.1 as JB suggests, then it will still work, even with the network card unplugged.

          IT-ADMINI 1 Reply Last reply Reply Quote 0
          • IT-ADMINI
            IT-ADMIN @Dashrender
            last edited by IT-ADMIN

            @Dashrender said:

            Yes.

            Let's assume DC2 is offline, but you want to see if you can run ADUC on DC2. When you run ADUC it uses DNS to try to open and failes.

            But if you put in 127.0.0.1 as JB suggests, then it will still work, even with the network card unplugged.

            i tried that, i put the primary DNS as 127.0.0.1 but still cannot open ADUC,

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            • DashrenderD
              Dashrender
              last edited by

              While you had both DCs on the network together, where you able to connect ADUC to DC2?

              IT-ADMINI 1 Reply Last reply Reply Quote 0
              • IT-ADMINI
                IT-ADMIN
                last edited by

                i have a question please : do i have an issue or not, in another word: does DC1 (who has FSMO) should be online in order for DC2 to work properly or it is not a condition ???

                DashrenderD 1 Reply Last reply Reply Quote 0
                • IT-ADMINI
                  IT-ADMIN @Dashrender
                  last edited by

                  @Dashrender said:

                  While you had both DCs on the network together, where you able to connect ADUC to DC2?

                  i'm able to open ADUC in DC2 only if DC2 can see DC1, as soon as i unplug DC2 from the network i cannot open ADUC
                  DC2 it is kind of a mirror right now, it is useless, it is nothing without DC1

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                  • DashrenderD
                    Dashrender @IT-ADMIN
                    last edited by

                    @IT-ADMIN said:

                    i have a question please : do i have an issue or not, in another word: does DC1 (who has FSMO) should be online in order for DC2 to work properly or it is not a condition ???

                    That is not a requirement.
                    and because you are having problems when you turn off DC1, it appears that your DC2 is broken.

                    IT-ADMINI 1 Reply Last reply Reply Quote 0
                    • DashrenderD
                      Dashrender @IT-ADMIN
                      last edited by

                      @IT-ADMIN said:

                      @IT-ADMIN 0_1455046058773_2016-02-09_222702.png

                      If possible, please show the above panel for DC1 next to DC2

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                      • IT-ADMINI
                        IT-ADMIN @Dashrender
                        last edited by IT-ADMIN

                        @Dashrender said:

                        @IT-ADMIN said:

                        i have a question please : do i have an issue or not, in another word: does DC1 (who has FSMO) should be online in order for DC2 to work properly or it is not a condition ???

                        That is not a requirement.
                        and because you are having problems when you turn off DC1, it appears that your DC2 is broken.

                        ah now i can see, so i have an issue here, damn glad to know that lol

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                        • IT-ADMINI
                          IT-ADMIN
                          last edited by

                          for the IP setting of DC1, unfortunately i'm home now, but i know its setting very well

                          DC1 :
                          IP : 192.168.15.250
                          Subnet: 255.255.255.0
                          gatway : 192.168.15.1

                          P DNS : 192.168.15.250
                          S DNS : 192.168.15.1

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                          • IT-ADMINI
                            IT-ADMIN
                            last edited by

                            the 2 site are connected via VPN

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                            • DashrenderD
                              Dashrender
                              last edited by

                              OK a possible huge issue is that you are pointing your secondary DNS to x.x.x.1, which is your default gateway, and unless you're using a Domain Controller as a default gateway is a very bad idea.

                              Windows machines should only ever point to your own DNS servers, more specifically, Windows DNS servers, assuming they are the backbone of your internal network.

                              If you put something like Google's DNS (8.8.8.8) as a secondary and the machine flips over to using that DNS server, that computer will never find your domain again until it's force to flip back, which will only happen on a reboot or a loss of internet connectivity.

                              Assuming DC2 is
                              IP 192.168.1.249
                              Subnet 255.255.255.0
                              DF 192.168.1.1
                              DNS1 192.168.1.249
                              DNS2 192.168.1.1 (change this to DC1 IP address)

                              I wonder if your DNS is working on DC2.

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                              • DashrenderD
                                Dashrender
                                last edited by

                                While both servers are on the network, Open DNS applet. Like ADUC switch to DC2. Check the DNS entries - are they there?
                                You can open another DNS applet and point it to DC1, then compare. They should be identical.

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                                • DashrenderD
                                  Dashrender
                                  last edited by

                                  Also, while you're at it, Open a command prompt on DC2 and run dcdiag

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                                  • IT-ADMINI
                                    IT-ADMIN
                                    last edited by

                                    sorry guys, it is 1.35 AM, i have to sleep now
                                    to be continued ...

                                    scottalanmillerS 1 Reply Last reply Reply Quote 1
                                    • scottalanmillerS
                                      scottalanmiller @IT-ADMIN
                                      last edited by

                                      @IT-ADMIN said:

                                      sorry guys, it is 1.35 AM, i have to sleep now
                                      to be continued ...

                                      2:30 am here. Still going.

                                      DashrenderD 1 Reply Last reply Reply Quote 0
                                      • DashrenderD
                                        Dashrender @scottalanmiller
                                        last edited by

                                        @scottalanmiller said:

                                        @IT-ADMIN said:

                                        sorry guys, it is 1.35 AM, i have to sleep now
                                        to be continued ...

                                        2:30 am here. Still going.

                                        Crazy man.

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                                        • scottalanmillerS
                                          scottalanmiller
                                          last edited by

                                          3:20am .... calling it a night.

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                                          • IT-ADMINI
                                            IT-ADMIN
                                            last edited by

                                            this is DC1 ip setting :

                                            0_1455088634499_2016-02-10_101609.png

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