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problem with secondary dns

    Question

  • hi,
      i'm looking for some informations about dns server in win 2003:

    1. if i stop the primary dns server for a domain, but the server remains up, the secondary server is used, or this happens only when the server goes down and the ip is not reachable anymore?

    2. how can i check that the secondary dns server is recognized as secondary namespace for the domains in the servers?

    the two servers are configured as dns servers for some internet website hosted.

    best regards,

      luca morelli

     

     

    Friday, July 16, 2010 8:28 AM

Answers

  • hi,
      i'm looking for some informations about dns server in win 2003:

    1. if i stop the primary dns server for a domain, but the server remains up, the secondary server is used, or this happens only when the server goes down and the ip is not reachable anymore?

     

    I don't fully understand whether the 1st question is regarding what happens on the client side, or what happens to the secondary read-only copy of the zone data on the DNS server holding the secondary, read only copy. I assume neither of the DNS servers are AD domain controllers.  

    This depends actually on the client side resolver. To explain, if a client machine, and I'm using a client in an internal infrastructure using these two servers as an example, has both DNS servers listed in its NIC properties, it will try to use the first one first. If the first DNS entry does not respond, essentially resulting in an NULL response, then the client side resolver will remove the first entry out of the 'eligible resolvers list' for 15 minutes (Windows XP SP2 and newer) and try the second entry. The 15 minute reset time can be adjusted in the registry.

    Also, if the first server goes down, the DNS server still holding the sedondary copy will continue to operate and service clients.

      

    2. how can i check that the secondary dns server is recognized as secondary namespace for the domains in the servers?

    the two servers are configured as dns servers for some internet website hosted.

    best regards,

      luca morelli

    You can use nslookup. It won't show if it's a "secondary" server, rather an authorative server for the domain name. The set q=ns sets nslookup to look for "ns" records that will show what nameservers are authorative, and the set q=soa sets it to look for the SOA (Start of Authority) should show the primary nameserver with additional information.

    Here's an example using intel.com:

    c:\>nslookup
    > set q=ns
    > intel.com
    Server:  vnsc-bak.sys.gtei.net
    Address:  4.2.2.2

    Non-authoritative answer:
    intel.com       nameserver = ns1.intel.com
    intel.com       nameserver = ns4.intel.com

    > set q=soa
    > intel.com
    Server:  vnsc-bak.sys.gtei.net
    Address:  4.2.2.2

    Non-authoritative answer:
    intel.com
            primary name server = ns1.intel.com
            responsible mail addr = hostmaster.intel.com
            serial  = 1395
            refresh = 55562 (15 hours 26 mins 2 secs)
            retry   = 905 (15 mins 5 secs)
            expire  = 604800 (7 days)
            default TTL = 14400 (4 hours)

    Ace


    Ace Fekay, MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003, Microsoft Certified Trainer, Microsoft MVP - Directory Services. This posting is provided AS-IS with no warranties or guarantees and confers no rights.
    • Proposed as answer by Tiger Li Monday, July 19, 2010 8:32 AM
    • Marked as answer by Tiger Li Friday, July 23, 2010 12:35 AM
    Friday, July 16, 2010 2:34 PM