No announcement yet.

Failover DC/DNS

  • Filter
  • Time
  • Show
Clear All
new posts

  • Failover DC/DNS

    I have two DC's also running as DNS1 and DNS2. DC1 is primary running WSE2008 SP1 32bit and DC2 is running WSE2008 R2 64bit. They are also both setup as global catalogs. Recently I noticed when DC1 goes down (as a reboot) my users can not login and lose internet connection as if they are not "failing over" to DC2 for authentication and using DC2 as secondary dns either. Any ideas???

  • #2
    Re: Failover DC/DNS

    Are the clients configured with both DNS servers in the TCP/IP settings?


    • #3
      Re: Failover DC/DNS

      Originally posted by joeqwerty View Post
      Are the clients configured with both DNS servers in the TCP/IP settings?
      Yes they are.


      • #4
        Re: Failover DC/DNS

        I googled and found this:

        Run 'ipconfig /registerdns' on the 2nd server.
        To verify DNS on the second server, set the DNS for a client manually to the 2nd server to see if it works.
        make sure DNS replication is working. The AD entries should be in both servers

        Run dcdiag, netdiag and repadmin in verbose mode.
        DCDIAG /V /C /D /E /s:yourdcname > c:\dcdiag.log
        netdiag.exe /v > c:\netdiag.log (On each dc)
        repadmin.exe /showrepl dc* /verbose /all /intersite > c:\repl.txt
        Look for the word 'fail'

        Also try:
        Netdom query fsmo
        Last edited by uk_network; 25th September 2013, 21:27.
        Please remember to award reputation points if you have received good advice.
        I do tend to think 'outside the box' so others may not always share the same views.

        MCITP -W7,
        MCSA+Messaging, CCENT, ICND2 slowly getting around to.


        • #5
          Re: Failover DC/DNS

          Might be a daft question but where is DHCP?

          What happens if you power off the main DC when users are connected to it? Can users still surf the web and connect to things?

          What DNS do you have set on your yours configuration?

          I presume DNS is installed and configured and replicating successfully on both servers?

          Do your DNS servers have the same config? Remember your forwarders need to be configured in a per server basis rather than singularly then replicated.

          Are there any firewall rules in place that would block DNS requests from DC2?

          Too many variables to really be able to help successfully IMO


          • #6
            Re: Failover DC/DNS

            Can you please post IPCONFIG/ALL from both DCs and a client?
            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

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