Name errors are common in the operation of DNS name servers. Name errors can occur because of the differences between what is acceptable in NetBIOS computer names and what is acceptable in DNS host names. NetBIOS computer names support a different character set than DNS host names, and by installation default, Windows NT Server and Windows NT Workstation are configured with a host name by using the NetBIOS computer name. In other words, the installation default for Windows NT Server and Windows NT Workstation is to configure the NetBIOS computer name as the DNS host name.
If the NetBIOS computer name contains invalid host name characters, Microsoft Windows NT Server and Windows NT Workstation attempt to correct the name by changing the invalid character in the host name to the - (hyphen) character. However, this change generates name resolution errors. For example, if your Web server NetBIOS computer name is Server#1, all attempts by remote TCP/IP network users to connect to the Web server by using the URL http://Server#1 will fail. They do so because the invalid # character is changed in the DNS host name to Server-1.
If computers in the zone managed by your Microsoft DNS server use NetBIOS names containing characters not supported in DNS host names, you must manually configure a valid host name on those computers.
Û To change a host name to a valid string of characters
1. Click the Start button, point to Settings, and click Control Panel.
2. Double-click the Network icon.
3. Click the Protocols tab.
4. In the Network Protocols list, click TCP/IP Protocol, and then click Properties.
5. Click the DNS tab.
6. In the Host Name box, type the corrected host name.
7. Click OK, click OK again, and then close Control Panel.
RFC 1912 defines the characters valid for DNS host names as: "Allowable characters in a label for a host name are only ASCII letters, digits, and the "-" character. Labels may not be all numbers, but may have a leading digit (e.g., 3com.com). Labels must end and begin only with a letter or digit. See RFC 1035 and RFC 1123.... The presence of underscores in a label is allowed in RFC 1033, except [RFC 1033] is informational only and was not defining a standard."
For more information about rules for creating valid host names, see RFC 1912, RFC 1035, and RFC 1123.