DHCP entries slow showing up in DNS

Discussion in 'DNS Server' started by ruic, Nov 18, 2009.

  1. ruic

    ruic Guest


    On my Win2k3 server I have both DHPC and DNS installed and DHCP is updating
    entries in DNS when it hands out ip addresses from the pool. However it
    takes a long time to update the DNS with the new A resource. Is there a way
    to speed it up? Sometimes it takes a couple of days.
    ruic, Nov 18, 2009
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  2. You should see a registration entry within 15 minutes, 30 minutes tops if in
    the same site with mutltiple DC/DNS servers, depending on the number of DCs
    that are DNS, etc. If expecting to see it in another site, it depends on
    replication schedule.

    How many DNS servers do you have? Which one is the client pointing to as the
    first entry in it's DHCP scope? Are you only using the internal DNS servers,
    or is there a mix of internal and external? Refreshing the console
    frequently until you see it appear?

    Is there a way to speed it up? NOpe. By default you should see it within a
    reasonable time as mentioned. Otherwise, there's a misconfiguration.


    This posting is provided "AS-IS" with no warranties or guarantees and
    confers no rights.

    Please reply back to the newsgroup or forum for collaboration benefit among
    responding engineers, and to help others benefit from your resolution.

    Ace Fekay, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA
    2003/2000, MCSA Messaging 2003
    Microsoft Certified Trainer

    For urgent issues, please contact Microsoft PSS directly. Please check
    http://support.microsoft.com for regional support phone numbers.
    Ace Fekay [MCT], Nov 19, 2009
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  3. ruic

    ruic Guest

    Thanks for your input.

    There's only one server with DNS it is the DC. After 15 minutes it does show
    up in the reverse lookup zone but not in the forward lookup zone.

    I did have the DHCP server giving out another DNS as the first listed while
    testing so as not to break users DNS resolution. I've now changed it back to
    the DC's DNS, I'll see if that's the problem and THAT was the problem!

    Thanks for you suggestions.

    ruic, Nov 25, 2009
  4. Rui,

    What is the "other" DNS server you were listing?

    First thing I must say, is NEVER use an ISP's DNS, the router as a DNS
    address, or anything else other than AD's DNS, which is your DC in your
    case. Otherwise, expect problems.

    If there are any event log errors, please post the EventID# and we can help
    you with fixing them.

    If you are listing anything other than your DC for DNS, it will be inviting
    problems with AD and authentication. I bet this is what the cause of entries
    not showing up in DNS. This is because AD must only use it's own internal
    DNS servers, because that is where all the AD info is stored and how clients
    "find" the DC, such as when they logon, authenticate to a printer, etc. So
    if you use an ISP's DNS server, the client will be asking the ISP's DNS
    server, "where is my DC so I can authenticate to logon," however the ISP's
    DNS server does not have info about your internal AD DCs.

    Also the Primary DNS Suffix must match the zone name. The zone name must
    allow updates.

    Other things that will cause problems with AD, authentication, DNS
    registration, etc, are:
    1. Multihomed DCs (a DC with more than one NIC and/or IP address, and/or
    with RRAS installed)- non SBS.
    2. Single label name AD DNS domain name (domain name is "domain" instead of
    required minimal format of "domain.something")
    3. ISA installed on a DC (non-SBS)
    4. DC is set to use some other DNS other than itself or other internal DCs
    for DNS.
    5. The Primary DNS Suffix on a machine (DC or client) must match the zone
    name, or no entries will register. If the DC's Primary DNS Suffix does not
    match the zone name, it is a condition called a "Disjointed Namespace."

    And no, resolution internally or for the internet, will not break if you
    only use your DC. DNS is designed to use Root Hints to resolve queries for
    external (internet) names.

    Configure a Forwarder for efficient internet resolution. This way it will
    use your ISP's for external resolution instead of Root Hints. If not sure
    how, follow this article:
    323380 - HOW TO Configure DNS for Internet Access in Windows Server 2003
    (including how to configure a Forwarder) :

    Some more info below to understand what I am talking about.

    Best practices for DNS client settings in Windows 2000 Server and in Windows
    Server 2003

    DNS and AD (Windows 2000 & 2003) FAQ:

    Common Mistakes When Upgrading a Windows 2000 Domain To a Windows 2003

    Ace Fekay [MCT], Nov 25, 2009
  5. ruic

    ruic Guest

    The other DNS server was a Netware server.

    I also found out that unchecking "Register this connection's addresses in
    DNS" in the DNS tab of Advanced TCP/IP settings makes things go a lot faster
    for computers not joined to the domain.

    The whole thing is working great now! Once again thanks for your help.

    ruic, Dec 3, 2009
  6. Glad to hear it is working now. If a machine is not joined, it won't have a
    Primary DNS Suffix, so with the connection to try to register, would be
    unnecessary, which I'm glad you unchecked it. You can add Dhcp Option 015
    and provide the domain name, which becomes the connection specific suffix,
    and the check box in IP properties of that connection, will register into
    DNS, as long as the zone allows Secure AND Unsecure updates.

    I haven't worked with Netware servers, but from what I understand, they do
    not support all the features that AD needs.

    Ace Fekay [MCT], Dec 3, 2009
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