Tuesday, May 27, 2014

404 Error Could Be Your DNS Cache

Overview

Your DNS cache stores the locations (IP addresses) of webservers that contain pages which you have recently viewed. If the location of the web server changes before the entry in your DNS cache updates, you will be unable to access the site. If you encounter a large number of HTML 404 error codes, you may need to clear your DNS cache. This will force your local computer to request new DNS information from its assigned nameservers rather than pull previously retrieved information from its local resolver cache.

How To Clear Your DNS Cache

The following methods allow you to remove old and inaccurate DNS information that may result in 404 errors.

Windows 8

  1. Press Win+X to open the WinX Menu.
  2. Right-click on Command Prompt and select Run as Administrator.
  3. Type the following command and press Enter:
    ipconfig /flushdns

Windows 7

  1. Click the Start button.
  2. Enter cmd in the Start menu search field.
  3. Right-click on Command Prompt and select Run as Administrator.
  4. Type the following command and press Enter:
    ipconfig /flushdns

Windows XP, 2000, or Vista

  1. Click the Start button.
  2. On the Start menu, click Run....
  3. If you do not see the Run command in Vista, enter run in the Search bar.
  4. Type the following command in the Run text box:
    ipconfig /flushdns

MacOS 10.7 and 10.8

  1. Click Applications.
  2. Click Utilities.
  3. Double-click the Terminal application.
  4. Type the following command:
    sudo killall -HUP mDNSResponder

MacOS 10.5 and 10.6

  1. Click Applications.
  2. Click Utilities.
  3. Double-click the Terminal application.
  4. Type the following command:
    sudo dscacheutil -flushcache

Once you clear your DNS cache, your local computer will query its nameservers and begin using newly changed information.