NT4 NetBIOS Domain name with a dot ("."), problems upgrading to 2003 ?

[EB]

Hi all

I was wondering if there could be a problem in migrating a NT4 Domain
called "KOH.DOMAIN" to Windows 200x.

NetBIOS and DNS have completely different namespaces and they should
not interfere between them, so netbios name could remain koh.domain
and dns domain name could be different (for example
kohinternational.com) during upgrade process.

Have you any experience of related problems with a dot in NT4 netbios
domain name with a dot ??? There should be a possible future issue
using a domain with this structure?

...and, most important thing, does microsoft support this kind of
upgrade? I have never seen some official document that states no
support is given for such domain name.

Thanks in advance
pinkblues

 

[Jorge de Almeida Pinto [MVP]]

I have never seen a NT4 domain with a dot. Yes for underscores, but never a
dot.

If I were you I would test this in a test environment to see what happens.

--

Cheers,
(HOPEFULLY THIS INFORMATION HELPS YOU!)
# Jorge de Almeida Pinto #
MVP Windows Server - Directory Services
BLOG --> http://blogs.dirteam.com/blogs/jorge/default.aspx

 

[Herb Martin]

"Jorge de Almeida Pinto [MVP]"

I have never seen a NT4 domain with a dot. Yes for underscores, but never a
dot.

If I were you I would test this in a test environment to see what happens.

I was thinking the same thing (as Jorge).

I almost wrote to say "you can't do that" but then
figured that if he says he did it, I guess he did.

Technically (almost) ANY 8-bit CHARACTER
can be part of a NetBIOS names but the COMPUTER
names are (much) more restrictive.

Windows Computer names are a subset (actually subpart
too) of legal NetBIOS names.

We should probably ask:

Does the DOMAIN NAME really have a "." DOT in it?

(What does it show in the drop down list on the logon screen?)

 

[Pink Blues]

Hi Herb

Well, let's start with something more precise
First of all: the domain name really has a "." dot in it! The domain
name is KOH.DOMAIN and it appears in dropdown list during logon
Second: when win2000 and winXP logon they search for KOH.DOMAIN via DNS
query for SRV records and then when they see there is no answer they
query for NETBIOS records 1b and 1c (monitored via sniffer).
Third. I've tried with a isolated test environment to upgrade such a
domain to 2003 and everything went fine. Also clients have been able to
succesfully logon to new "kohinternational.com" / "KOH.DOMIAN" domain.
Fourth. I've also tried to establish a two way trust relationship
between a 2003 domain and NT4 domain and 2003 domain controller, during
trust establishment had the same behaviour than xp wks, i.e. 2003 dcs
first tried to lookup for _ldap._tcp.koh.domain and then when they did
not get any answed, they looked up for 1c and 1b NetBIOS records.

In conclusions: it seems that "." dot in name has the same behaviour
than "_" underscore in name.
My question is: there could be some issue in future that it seems to be
hidden now?
Does microsoft support such kind of domain name?
There is NO document from microsoft that explicitely denies this kind
of name, but as you correctly said, it is not a best practice, neither
there are many companies in this situation

 

[Herb Martin]

Hi Herb

Well, let's start with something more precise
First of all: the domain name really has a "." dot in it! The domain
name is KOH.DOMAIN and it appears in dropdown list during logon
Second: when win2000 and winXP logon they search for KOH.DOMAIN via DNS
query for SRV records and then when they see there is no answer they
query for NETBIOS records 1b and 1c (monitored via sniffer).
Third. I've tried with a isolated test environment to upgrade such a
domain to 2003 and everything went fine. Also clients have been able to
succesfully logon to new "kohinternational.com" / "KOH.DOMIAN" domain.
Fourth. I've also tried to establish a two way trust relationship
between a 2003 domain and NT4 domain and 2003 domain controller, during
trust establishment had the same behaviour than xp wks, i.e. 2003 dcs
first tried to lookup for _ldap._tcp.koh.domain and then when they did
not get any answed, they looked up for 1c and 1b NetBIOS records.

External trusts are generally NetBIOS based so that makes sense,
and is mildly fascinating.

In conclusions: it seems that "." dot in name has the same behaviour
than "_" underscore in name.
My question is: there could be some issue in future that it seems to be
hidden now?

I am going to cop out and say: "Could it?" Certainly but I have no
specific information.

Reason: I have a (personal) rule for myself and my clients...

Always use a NetBIOS-computer/user/domain/workgroup names
that follow the following STRICT patten:

1) First character Alphabetic
2) Subsequent characters Alphanumeric
3) Maximum characters 14 (not even 15)

I made this rule long ago (NT 3.5x) days and so have never seen
any of the problems people experience with other name choices.

This makes me stupid (i.e., inexperienced) with such name problems.

Does microsoft support such kind of domain name?

I suspect not, but you need to ask one of the Support people (not me.)

There is NO document from microsoft that explicitely denies this kind
of name, but as you correctly said, it is not a best practice, neither
there are many companies in this situation

Right. One is too many.

If I could reasonably change it now, I would -- UNLESS I knew the life
of the NT4 domain was very limited (months not years.)


--
Herb Martin, MCSE, MVP
Accelerated MCSE
http://www.LearnQuick.Com
[phone number on web site]

 

[Pink Blues]

External trusts are generally NetBIOS based so that makes sense,

and is mildly fascinating.

well, actually only if made between 2k/2k3 and NT4

I am going to cop out and say: "Could it?" Certainly but I have no
specific information.

and that's where my anxiety comes out from!

Reason: I have a (personal) rule for myself and my clients...

oh, great rules, but the problem is always the same:
someone else makes the mistake and you are called to resolve it
actually in my experience this is the second time I have seen
such kind of name in 6 years.

If I could reasonably change it now, I would -- UNLESS I knew the life
of the NT4 domain was very limited (months not years.)

Well, this domain is operational from 2 or 3 years now.
Right now this domain has to be migrated or upgraded to 2003.
I'm actually suggesting to this customer a new creation from
scratch, also because number of client is relatively small (150) and
reacling file servers it does not seem to be a great problem.
ADMT is not a good solution for many reasons I cannot explain here.

BTW, I do really find strange that no-one has ever user this kind
of name worldwide, and Microsoft has never published a document with
"DOs and DONTs" in using NetBIOS names :-S

A "simple suggestion" or a "best practice" or a "reccomendation" ARE
NOT a requirement! Microsoft has not understood this fact yet! As
usual.

 

[Herb Martin]

well, actually only if made between 2k/2k3 and NT4

Well there are only 3 choices, 2k, 2k3, and NT4 and external
trusts between any (pair) of them are generlly based on NetBIOS.

[External trusts DO NOT EQUAL Forest trusts]

and that's where my anxiety comes out from!


oh, great rules, but the problem is always the same:
someone else makes the mistake and you are called to resolve it
actually in my experience this is the second time I have seen
such kind of name in 6 years.

Well, this domain is operational from 2 or 3 years now.
Right now this domain has to be migrated or upgraded to 2003.

A true migration will be tough if the other sice won't deal with
such a name.

I'm actually suggesting to this customer a new creation from
scratch, also because number of client is relatively small (150) and
reacling file servers it does not seem to be a great problem.
ADMT is not a good solution for many reasons I cannot explain here.

Might be one of the few exceptions to my rule for "always default
to upgrading domains."

BTW, I do really find strange that no-one has ever user this kind
of name worldwide, and Microsoft has never published a document with
"DOs and DONTs" in using NetBIOS names :-S

A "simple suggestion" or a "best practice" or a "reccomendation" ARE
NOT a requirement! Microsoft has not understood this fact yet! As
usual.

Truthfully, I didn't think NT would let you do that.