DNS Records with Same Name as Subdomain Are Moved or Missing

ID: Q231306

The information in this article applies to:

Microsoft Windows NT Server version 4.0
Microsoft Windows NT Server, Enterprise Edition version 4.0

SYMPTOMS

When you create a DNS record that has the same name as a subdomain, the record may be missing. For example:

You have a DNS domain called mycompany.com, and a subdomain called sales.mycompany.com that contains some records (for example, host1.sales.mycompany.com). You want the name sales.mycompany.com to be resolved to a host (A or CNAME) or a mail server (MX), so you select mycompany.com and add a record named sales.

When the record is created, it is displayed as "sales" in mycompany.com. After you refresh the view, the entry is missing. The record is displayed in sales.mycompany.com if it is either:

A non-delegated subdomain.

A delegated subdomain, but the DNS server is the primary server for the zone.

If the sales.mycompany.com domain is a delegated subdomain and the primary server is on a different system, the record is not written to any zone file. No error message is displayed.

CAUSE

This behavior occurs because the new records in the currently selected domain are displayed in the DNS Administration tool. After you refresh the view, the DNS Administration tool applies the same rules that the DNS server component uses.

The DNS server decides where to put the record based on the record's fully qualified domain name (FQDN). The sales.mycompany.com record is placed in the sales.mycompany.com subdomain with an empty name.

If sales.mycompany.com is not delegated, it is displayed in the zone file as expected, but is displayed in the graphical DNS Administration tool with the FQDN in sales.mycompany.com (which actually means an empty name).

If sales.mycompany.com is the root of a zone, it appears with the "@" character in the zone file. If the local server is not the primary server for the delegation, the DNS server assumes it can add the record successfully but the request is not successful and no error message is displayed.

RESOLUTION

To work around this problem, do not add records that have the same name as a subdomain or a delegation. Instead, go directly to the name in question and add the record with an empty name.

If the subzone is delegated to a different primary server, connect to it remotely.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

Additional query words:

Keywords :
Version : winnt:4.0
Platform : winnt
Issue type : kbbug