What type of names are supported in Windows 2000/2003 DNS?

Posted on January 8, 2009 by Daniel Petri in DNS with

When implementing Windows 2000 and Windows Server 2003 DNS infrastructure DNS naming is another major factor which has to be taken into account. DNS names are restricted to the characters A to Z, digits, and the hyphen(-). The first character of a DNS label can be either a letter or a digit according to RFC 1123.

Microsoft’s machine naming is based on NetBIOS names which supports a much wider character set the underscore (_), and the exclamation mark (!). The underscore is particularly common in Windows-based networks, and when these are combined with UNIX-based networks problems might surface.

Microsoft’s Windows 2000/2003 DNS supports alternate character set defined in RFC 2181 which specifies that a DNS label can be any binary string that does not necessarily need to be interpreted as ASCII. Thus Microsoft suggests the use of UTF-8 character encoding that is a superset of ASCII and a translation of Unicode.

To change the naming standard in W2K DNS:

  1. In the DNS console, right-click on DNS server.
  2. Select Properties.
  3. Select Advanced tab.
  4. Make your choice in the Name Checking drop-down list:

  • Strict RFC (ANSI) : RFC 1123, A-Z, 0-9, – (dash).
  • Non-RFC (ANSI): adds underscore to ANSI set.
  • Multibyte (UTF8) : allows UTF8 characters (Microsoft naming standard).
  • Any names : allows any character.

For a strictly private network, Microsoft’s suggested Unicode standard works well. If its a strictly Microsoft network. You again have to decide on whether enforcing standards on the Microsoft world which the heterogeneous network needs or whether to have dual support.