Can't Use Periods in DNS Host Names

• Microsoft Windows NT Workstation version 3.5
• Microsoft Windows NT Server version 3.5

SUMMARY

Both the Help file and the manual for the TCP/IP Domain Name Server (DNS) configuration are incorrect in describing the type of characters that can be used in the host name. The documentation says that both the hyphen and period can be used. However, attempting to use a period in the host name will result in an error message indicating the parameter is incorrect.

The TCP/IP manual says:

   In the DNS Configuration dialog box, you can, optionally, type a name in
   the Host Name box (usually your computer name):

   The name can be any combination of A-Z letters, 0-9 numerals, and the
   hyphen (-) plus the period (.) character used as a separator. By
   default, this value is the Windows NT computer name, but the network
   administrator can assign another host name without affecting the
   computer name.

   Host Name

   Optionally, type a name in the Host Name box (usually your computer
   name). The name can be any combination of A-Z letters and 0-9 digits,
   plus the hyphen (-) and period (.) characters.

   Using a period in the host name would be interpreted as a separator, and
   result in an error message.

   Periods are only allowed when they serve to delimit components of
   "domain style names".

MORE INFORMATION

Under Windows NT 3.5, the host name is set to the computer name (or NetBIOS name) by default. You can change the name used from the Network section of Control Panel. Select TCP/IP Protocol, choose Configure, and then choose DNS to see the host name. You can specify both the host and domain names.

NOTE: The domain name listed here should not be confused with the term "domain name" as it is used in a Windows NT domain. This is the domain name set by the TCP/IP DNS.

Reference(s):

More information on DNS can be found in the DNS RFC 1034.