How to Clean and Configure Windows XP DNS Cache

Cannot find server DNS error message

This article is intended for Windows OS users.

Windows XP comes with a cache storing all DNS addresses that have been searched and viewed recently. Whenever a web browser requests an URL, Windows XP searches in the local cache first, to check if the URL is stored there before commanding the external address server used by your internet service provider (ISP). If it finds the requested URL locally in the DNS cache it uses that IP. This is to save time downloading identical files and to prevent web traffic jam.

The default period for storing an IP address in the DNS cache is 24 hours. A problem can occur if the address or the name for an URL changes before the 24 hour time frame expires. In this case, you will receive a DNS error message if you try to connect to the URL.

Following are steps to clear the DNS cache and configure the DNS resolver cache.

Difficulty:

Moderately Challenging

Instructions

Things You'll Need

• Windows platform PC
• Windows XP OS
• Some PC troubleshooting experience helpful
• Instructions in this article

1. - - DNS Cache Cleanup - -

   WinXP comes with a command line utility called "ipconfig" (IP Configure), in that it has a selector named "flushdns" (Flush DNS), for deleting the items in the cache. You open a command prompt and enter this: ipconfig/flushdns, it will empty the cache. A cleaned cache sometimes helps boost your Internet speed.

   NOTE: Instructions to open a command prompt - - Click on the Start button on the Windows XP menu bar, then click Run. Enter this in the text area: cmd.

2. - - DNS Resolver Cache Configure - -

   You can minimize the IP address storing time in the DNS cache, also known as reducing the "time to live" (TTL).

   You need to edit the registry item: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNSCache\Parameters, which has the control over the configuration.

   Note that the DWORD value MaxCacheTtl is used to control the items saving time in the DNS cache. The default value in the absence of an entry is 86,400 seconds; equivalent to a day's time (24 hours). To reduce the storing time, create the entry then enter your preferred time in seconds.

   WARNING: This requires going into the Windows Registry, thus should be done only by those know how to restore their Registry.

3. Cleaning and/or configuring the DNS cache can save you time and prevent your browser having problems finding URLs next time when you are online.

   You may also receive a DNS error message and it is caused by the site or page you are trying to access, so the problem is not always on your side. It could be that the site or page is on maintenance/checkup or having some other problems. If this is the case, wait 5-10 minutes and try again to access the website or web page.

Tips & Warnings

• Computer terminology: Cache - - A temporary storage area (folder) for frequently used or recently visited data. Cache is used by the operating system to quickly transfer data between the hard disk, CPU and the RAM.

• Computer terminology: DNS - - Domain Name System (or Service, Server). Is an Internet service that converts domain names into IP addresses. For example, http://www.myarticles.net might translate to 196.135.202.6