Single-Label DNS Names: Why

Archived from groups: microsoft.public.win2000.dns (More info?)

Can someone explain me why some people are using Single-Label DNS Names ??

What cousl be the impact on the whole AD Infra etc ??

Also, does this invlove something when migrating from EX5.5 to EX2003 and
Windows 2000 to Windows 2003.

Maybe is this the wrong forum.. will also make a post in the exchange forum.

Anyway thx
4 answers Last reply
More about single label names
  1. Archived from groups: microsoft.public.win2000.dns (More info?)

    > Can someone explain me why some people are using Single-Label DNS Names ??

    Probably because they haven't read the "best practices".

    > What cousl be the impact on the whole AD Infra etc ??

    Extra admin work
    Future MS technologies that are designed away from the single label domain
    name model that became obsolete in Win 2k.

    > Also, does this involve something when migrating from EX5.5 to EX2003 and
    > Windows 2000 to Windows 2003.

    Not totally sure what you are asking here.

    hth
    DDS W 2k MVP MCSE

    "Olivier César" <olivier.cesar@scarlet.be> wrote in message
    news:%23MUvXiNTFHA.228@TK2MSFTNGP12.phx.gbl...
    > Can someone explain me why some people are using Single-Label DNS Names ??
    >
    > What cousl be the impact on the whole AD Infra etc ??
    >
    > Also, does this invlove something when migrating from EX5.5 to EX2003 and
    > Windows 2000 to Windows 2003.
    >
    > Maybe is this the wrong forum.. will also make a post in the exchange
    > forum.
    >
    > Anyway thx
    >
    >
  2. Archived from groups: microsoft.public.win2000.dns (More info?)

    I mean. If i try to upgrade from 5.5 to 2003, what could be the impact ??


    "Danny Sanders" <Danny.Sanders@NO-SPAMcpcmed.org> wrote in message
    news:%238pHE6NTFHA.3152@TK2MSFTNGP12.phx.gbl...
    >> Can someone explain me why some people are using Single-Label DNS Names
    >> ??
    >
    > Probably because they haven't read the "best practices".
    >
    >> What cousl be the impact on the whole AD Infra etc ??
    >
    > Extra admin work
    > Future MS technologies that are designed away from the single label domain
    > name model that became obsolete in Win 2k.
    >
    >> Also, does this involve something when migrating from EX5.5 to EX2003 and
    >> Windows 2000 to Windows 2003.
    >
    > Not totally sure what you are asking here.
    >
    > hth
    > DDS W 2k MVP MCSE
    >
    > "Olivier César" <olivier.cesar@scarlet.be> wrote in message
    > news:%23MUvXiNTFHA.228@TK2MSFTNGP12.phx.gbl...
    >> Can someone explain me why some people are using Single-Label DNS Names
    >> ??
    >>
    >> What cousl be the impact on the whole AD Infra etc ??
    >>
    >> Also, does this invlove something when migrating from EX5.5 to EX2003 and
    >> Windows 2000 to Windows 2003.
    >>
    >> Maybe is this the wrong forum.. will also make a post in the exchange
    >> forum.
    >>
    >> Anyway thx
    >>
    >>
    >
    >
  3. Archived from groups: microsoft.public.win2000.dns (More info?)

    "Olivier César" <olivier.cesar@scarlet.be> wrote in message
    news:ONT1pqOTFHA.3176@TK2MSFTNGP09.phx.gbl...
    > I mean. If i try to upgrade from 5.5 to 2003, what could be the impact ??
    >

    For one, the DNS doesn't work completely correctly in AD
    with single label names.

    Start here:

    Single Label domain zone names are a problem Google:
    [ "SINGLE LABEL" domain names DNS 2000 | 2003 microsoft: ]


    --
    Herb Martin, MCSE, MVP
    Accelerated MCSE
    http://www.LearnQuick.Com
    [phone number on web site]
  4. Archived from groups: microsoft.public.win2000.dns (More info?)

    Olivier César wrote:
    > I mean. If i try to upgrade from 5.5 to 2003, what could be the
    > impact ??

    Impact? If you do not choose the correct format for the domain name when
    upgrading to AD, you are inviting yourself for numerous issues and
    implications to occur. Do a search in the newsgroups on single label names.
    As Herb said, do the same with Google. You'll find much written out there on
    it.

    It seems you are also referring to Exchange. We need to work on AD first.
    Exchange uses the default DNS domain name as the default recipient policy
    email suffix. That doesn't matter if your domain name is different
    externally because you can add whatever suffix you want in there, make sure
    the MX record is pointing to this machine, and it will receive mail for that
    domain name. But Exchange 2000/2003 relies on AD. If AD fails, Exchange
    fails. AD relies on DNS. If DNS fails, AD fails, therefore Exchange fails.
    Single label names will cause DNS to fail, therefore AD and Exchange will
    fail in concert. Nasty circle, ain't it?

    Quick guideline:
    DNS is hierarchal. It's based on a "tree" structure. It starts from the top
    of an "upside down" tree with the Root. That's depicted with by a dot ".".
    The next level down is your first level name, or better known as the TLD
    (Top Level Domain) name, such as com, edu, net, org, and others that you can
    make up for an internal infrastructure such as corp, local, internal, etc.
    Then the next level is the second level names, such as microsoft,
    macromedia, intel, etc.

    The name microsoft.com. So we have a basis so far that is tree based. Notice
    the period after the com? The depicts the Root. Even if you don't put it in,
    it's understood to be there. "microsoft.com." It has a hierarchal structure.

    However, NT4 didn't require this. Many admins who upgraded to AD didn't do
    their research and wound up choosing a single label name, such as
    "microsoft" instead of the required format. There is no hierarchal structure
    with a single label name. DNS servers do not know what to do with it. A DNS
    server will assume it is a TLD. During a query, and especially during the
    Dynamic DNS update process, when a DNS server receive a request for a single
    lable name, it assumes it's a TLD, then it will start querying the Root
    Servers excessively to determine if there is such a TLD as "microsoft". This
    causes excessive traffic to the Root servers. Microsoft recognized this
    after ISC did a study and determined all the excessive unnecessary traffic
    the Roots were receiving were from installations with single label names.
    When Win2000 SP4 was released, there was a stop put into it to disallow DNS
    updates for single label name AD DNS domain names. This was only fair to
    being a good Internet citizen in the community.

    XP Pro has major issues with single label names. Queries may even fail with
    single label names using XP Pro. That would cause problems with user logons,
    accessing files, printers, and especially GPOs.

    Here's one for you. The LdapIpAddress record, which looks like this:

    domain.com
    (same as parent) A 192.168.5.200

    That is used when domain service locations are queried for certain
    functions, such as GPOs. When a client side GetGpoList function runs during
    logon, it queries for:
    \\domain.com\sysvol\domain.com\policies\{GuidOfGpoPolicie...}

    If it were a single label name, it would look like this:
    \\domain\sysvol\domain\policies\{GuidOfGpoPolicie...}

    So it would treat it as a NetBIOS name. Major issues there, especially with
    XP.

    Sure you can go to each domain controller and each XP and W2k machine and
    make registry entries to force it to update. But that is way too much
    administrative overhead.

    Therefore, if you have a single label name, numerous issues can occur, such
    as the lack of Dynamic Registration, a key integral part of AD. So as the
    requirements go, AD requires DNS, if DNS doesn't function properly, it will
    cause major problems with AD. If you have a single label name, DNS will be
    problematic, in turn AD will be problematic.

    So do yourself a favor and get those good night rests that admins with
    single label names do not get and name your domain properly, for more than
    one reason, even if it's just best practices.


    --
    Regards,
    Ace

    Please direct all replies ONLY to the Microsoft public newsgroups
    so all can benefit.

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

    Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
    Microsoft Windows MVP - Windows Server - Directory Services

    Paramount: What's up with taking Enterprise off the air??
    Infinite Diversities in Infinite Combinations.
    =================================
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