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  • AD 2003 + DHCP to 2008 R2 migration

    Hi folks,
    Our environment consists of two DCs, 2003 SP2. Both running DNS, both GCs. One of them is FSMO holder and the other is DHCP. All clients are XP sp3/2003 sp2 and up. Exchange is 2003 SP2, will be upgraded in a couple of months.
    We are about to migrate this environment to 2008 R2. I've read several articles about migrating DC + DNS, seperate article about DHCP migration using the R2 migration tools (PS script). The trick is that I need to keep current DC names and IPs.

    I was wondering if anyone had done it already. I realize there will be some downtime , we are OK with that, doing one DC at a time.

    The scenario we plan is this:
    0) Document all settings of entities involved. Backup.
    1) Install a third 2003 DC and make it GC and DNS. Transfer FSMO roles to it. This server will serve us in case of a slim possibility some app would not like to be authenticated against 2008 R2 server - we will point it to this server.
    2) Install two member 2008 R2 servers as future DCs with temp names and IPs (tempdc1, tempdc2). Run "prep"s (forest, domain+gp). Let it replicate.
    3) DC1: Wait after work hours (it's our primary DNS). Demote+remove DNS, restart, rename + change IP, restart.
    4) tempdc1: change ip, rename to DC1. Promote to DC, install DNS, reboot, verify replication, make it a GC, reboot again, test AD+DNS.
    5) Go home and hold fingers crossed that tomorrow you will not get fired
    6) Come to work and drink a large cup of coffee.
    7) Install server 2008 R2 migration tools on DC2.
    8 ) DC2: Wait until after work hours (this one is DHCP). Export configuration via PS script. Copy it to tempdc2. Stop dhcp, uninstall it. Reboot if needed. Demote DC + remove DNS. Reboot, change computer name and IP.
    9) tempdc2: Give it IP and name of DC2. Promote to DC + DNS. Reboot, make GC, reboot. Test DNS and AD. Use Win2008 R2 migration tools to restore DHCP migration file + install DHCP (they claim it's done by the restore). Start DHCP and test it. Reboot if needed.
    10) Wait couple of weeks and take back FSMO. Shut down DC3 for a few days.
    11) Start DC3 and demote it + remove DNS. Rename it to "sad-old-server".
    12) Raise AD + forest levels to 2008 R2.
    13) Start reading Exchange 2010 migration guide.

    Any comments, remarks, pitfalls and suggestions are welcome.
    Regards,
    Leonid

    MCSE 2003, MCITP EA, VCP4.

  • #2
    Re: AD 2003 + DHCP to 2008 R2 migration

    I didn't read your entire plan and I've not done this with Exchange involved, but why not perform an in-place upgrade of the current DC's to W2K8R2? I've done an in-place upgrade with no ill effects whatsoever. The upgrade was surprisingly simple, quick, and problem free.

    Comment


    • #3
      Re: AD 2003 + DHCP to 2008 R2 migration

      Hi joeqwerty,
      Usually I am against in-place upgrade. Anyway, bot DCc are x86 and 2008 R2 is x64 platform. Forgot to mention that the are 32 bit.
      http://www.microsoft.com/windowsserv...ion-paths.aspx
      "Cross-architecture in-place upgrades (for example, x86 to x64) are not supported."
      No luck here
      BTW, exchange is not involved in the current scenario - it will continue operating as usual as long as there are GCs around and it's exch. 2003 SP2.
      http://technet.microsoft.com/en-us/l.../ff728623.aspx
      Last edited by venom83; 4th November 2010, 18:02. Reason: typo
      Regards,
      Leonid

      MCSE 2003, MCITP EA, VCP4.

      Comment


      • #4
        Re: AD 2003 + DHCP to 2008 R2 migration

        Gotcha. True enough that you can't upgrade from 32bit to 64bit.

        Comment


        • #5
          Re: AD 2003 + DHCP to 2008 R2 migration

          Yep.
          Any thoughts on the upgrade procedure?
          Regards,
          Leonid

          MCSE 2003, MCITP EA, VCP4.

          Comment


          • #6
            Re: AD 2003 + DHCP to 2008 R2 migration

            More important question: had anyone done a DHCP migration to 2008 R2 DC using 2008 R2 migration tools?
            Regards,
            Leonid

            MCSE 2003, MCITP EA, VCP4.

            Comment


            • #7
              Re: AD 2003 + DHCP to 2008 R2 migration

              Upgrade domain to server 2008

              then transfer your FSMO roles

              with regards to moving over your dhcp , can you not just install DHCP on your new server then, simply export and import the DHCP Database

              then authorize DHCP on thje new server and disable on the old server?
              Allen White
              MCSE,MCSA,MCITP,MCTS,CCA,CCSP,VCP

              Comment


              • #8
                Re: AD 2003 + DHCP to 2008 R2 migration

                Originally posted by Allenwhite78 View Post
                Upgrade domain to server 2008

                then transfer your FSMO roles

                with regards to moving over your dhcp , can you not just install DHCP on your new server then, simply export and import the DHCP Database

                then authorize DHCP on thje new server and disable on the old server?
                Thanks for your will to help
                a. You cannot use GUI backup/restore between different windows versions. You can use "netsh dhcp server export %path\filename% all"
                http://blogs.technet.com/b/teamdhcp/...rver-2008.aspx
                b. This process will not preserve IP address of the servers. Changing DHCP address is equal to changing ip helper address in 30 different vlan configuration on our routers. I would like to skip this procedure.
                http://routergod.com/trinity/
                Last edited by venom83; 4th November 2010, 18:02. Reason: mistyped
                Regards,
                Leonid

                MCSE 2003, MCITP EA, VCP4.

                Comment


                • #9
                  Re: AD 2003 + DHCP to 2008 R2 migration

                  TBH I rarely bother migrating the DHCP database if I have time. How about:
                  1) Reserve half the scope (e.g. 120-254 on a class C) on the original DHCP server and reduce the lease to say 8 hours
                  WAIT for all clients to renew, so no leases in the reserved range
                  2) Authorise the new DHCP server, reserve the other half of the scope (e.g. 1-120)
                  3) Unauthorise the first DHCP server
                  4) Wait until clients are picking up addresses on the new one, then decommission the old DHCP server (doesnt matter about existing leases as the renewal will pick up a new address
                  5) Wait till ALL clients are on the new server, then remove the reservation
                  Simples
                  Tom Jones
                  MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
                  PhD, MSc, FIAP, MIITT
                  IT Trainer / Consultant
                  Ossian Ltd
                  Scotland

                  ** Remember to give credit where credit is due and leave reputation points where appropriate **

                  Comment


                  • #10
                    Re: AD 2003 + DHCP to 2008 R2 migration

                    Ossian, your method is also good for people less lazy than me
                    Just kiddin'; I really want to avoid touching the ip helper configuration on the routers and that means leave the original server IP.

                    Look, guys, there are obvious a few ways to go with this. What I really wanted to know is if anyone had the pleasure to use 2008 R2 migration tools to transfer DHCP server on a DC.
                    If no, I'll be probably running the simulation next week and will post the results.
                    Regards,
                    Leonid

                    MCSE 2003, MCITP EA, VCP4.

                    Comment


                    • #11
                      Re: AD 2003 + DHCP to 2008 R2 migration

                      Not next week, but still

                      I've ran the lab and everything went 100 percent. No problems whatsoever. Some error events in dcdiag were quickly resolved by google as MS recommends to ignore them. Also some errors will be resolved by themselves, just need to give them a few hours (replication etc).

                      I'm doing the production upgrade this week. The work plan largely remains the same as in the first post.

                      Thanks for all the input, guys.
                      Regards,
                      Leonid

                      MCSE 2003, MCITP EA, VCP4.

                      Comment


                      • #12
                        Re: AD 2003 + DHCP to 2008 R2 migration

                        I do realize the post is quite old, however maybe it will help someone.
                        I did the upgrade, all went well. One thing I didn't took into account and this is probably my fault for cutting corners is the configuration of DNS scavenging. This config is something that is configured per server, mostly one is enough, but you still need to configure it as it will not be enabled automatically.
                        Here is a good read about the topic:
                        http://blogs.technet.com/b/networkin...e-patient.aspx
                        Regards,
                        Leonid

                        MCSE 2003, MCITP EA, VCP4.

                        Comment

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