Cannot Resolve Host Name to IP Address After You Replace the Hosts File (320845)


The information in this article applies to:

  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
This article was previously published under Q320845

SYMPTOMS

When you try to resolve a new host name entry in the Windows 2000 Hosts file to the corresponding IP address, you may be unsuccessful.

When you use the Ping.exe utility to try to confirm connectivity to the host, you may receive the following message, where hostname is the name of the host with which you try to connect:

Unknown host hostname.

When you "ping" the IP address of the host, you are successful and you receive the echo response that you expect.

CAUSE

This behavior may occur when the following conditions are true:
  • You create a host entry in a copy of the Hosts file or in a new Hosts file.

    -and-
  • You copy that Hosts file to the original folder, overwriting the original Hosts file.
NOTE: By default, the Windows 2000 Hosts file is stored in the following location:

%Systemroot%\system32\drivers\etc

RESOLUTION

To work around this issue, use one of the following methods.

Method 1: Flush the DNS Resolver Cache

After you replace the Hosts file, or copy a new Hosts file into the %Systemroot%\system32\drivers\etc folder, flush the DNS Resolver cache. To do so, follow these steps:
  1. Click Start, click Run, type cmd in the Open box, and then click OK.
  2. At the command prompt, type ipconfig /flushdns, and then press ENTER. You receive the following message:

    Successfully flushed the DNS Resolver Cache.

  3. Type exit, and then press ENTER to close the command prompt.

Method 2: Restart the Computer

After you replace the Hosts file or copy a new Hosts file into the %Systemroot%\system32\drivers\etc directory, restart the computer.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

223413 Options for Ipconfig.exe in Windows 2000

Modification Type:MajorLast Reviewed:11/19/2003
Keywords:kbprb KB320845
©2003 Microsoft Corporation. All rights reserved.