Connection via a Router to a NT Domain Server

by Johannes Helmig [Published on 24 March 2001 / Last Updated on 24 March 2001]

When a Windows95/98 or WindowsNT4 system is connected on the same network-cable as
the domain-server, then the system will know the IP-address of the domain-server from the
workgroup/domain broadcasts (example: Pc#1 and #2 in the drawing below)

If your system (example in the above drawing: PC#3,4,5) is connected to a different
network segment, which is connected via a router to the server-segment, then your system
will not know the IP-address of the Domain-server, because broadcast messages are
NOT passed through routers.

But to logon, you need to define the Domain-server:

Your system needs to know on how to "find the way" to the server and to the Domain-
controller (which could be the same, but could be different systems).

First, configure your TCP/IP with the proper Gateway/Router information and verify
using PING with the IP-address, that you have a connection to your server.

Then you need a Translation service to convert a name (like the Domain-server name)
to an IP-address. That could be a DNS-server, if your Domain-server is also configured
as a DNS-server.

For a configuration without a DNS-server, you can define this name-translation manually
by defining them in LMHOSTS:
Look on Windows95/98 in your WINDOWS-directory, on NT4 in Windows\system32\drivers\etc
for the file LMHOSTS (if it does not exist, look for the file LMHOSTS.SAM and make a copy
calling the copy LMHOSTS)
, then edit LMHOSTS:
I use on purpose the DOS-EDIT in a Command-Windows ("DOS-box"):

scroll to the end of the file, add first the IP-address of the server and the servername
(example: <tab-key> server-name)
Enter the IP-address of your domain-server, followed by the Domain-Name:
A domain-name is identified to have as character ( the NetBIOS Suffix ) a
hexadecimal values of 0x1c.
To enter such a name, put the full name in quotation makes, type first the domain-name,
fill it up with blanks to 15 characters, then add \0x1c.

More information on these special codes in LMHOSTS is available in the Microsoft
Knowledge base:
- Q150800 : Domain Browsing with TCP/IP and LMHOSTS Files
- Q180094 : How to Write an LMHOSTS File for Domain Validation and Other Name Resolution Issues
- Q163409 : NetBIOS Suffixes (16th Character of the NetBIOS Name )

(to make it easy, I added above the ip-address lines a comment-lines counting character positions
(# 1234567890123456), using it as a guide when typing the domain-name with EXACTLY 16 characters,
and using the DOS-editor, I do not have to bother with windows-fonts with variable-width characters)

If you prefer to work with NOTEPAD:

make sure it used a fixed-width font.

On NT4 I got on some systems
this display of NOTEPAD:
On NT4, select fromthe menu
"Edit" to "Set Font"
then select the fixed-width
font "Fixedsys" to change
the font for easy alignment
of columns.

Unless LMHOSTS, which is immediately ready-for -use after an update, you will either
have to reboot or run the command: "nbtstat -R" (very important: CAPITAL R)
to make the new values in LMHOSTS active.

To verify that the information is stored properly, you can run the command: "nbtstat -c".

You should be able to logon to your domain-server via the routers.

See Also

The Author — Johannes Helmig

Dr.Johannes Helmig is working as Director, Technical Knowledge Management in the Belgium office of Gerber Technology where he is involved in Customer Service and internal training, with special interest in Networking.


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