Flushing DNS Cache


  • Applies to: All Service Types
    • Difficulty: Easy
    • Time Needed: 10
    • Tools Required: None

Introduction

When your computer visits a website for the first time, it stores the website's DNS information in a local cache. The next time you visit that website, it will first look at this cache for any previous visits. While this is a very efficient method it can cause problems if DNS information has just recently changed. In this case you might want to "flush" your local cache to force your local computer to find this new DNS info.

Instructions

Below are instructions unique to particular operating systems. If you would like to contribute instructions for any system not listed here please feel free to comment on this article and we will include them in a future revision.

Microsoft Windows

(Win 7/Vista/XP/Win ME/Win 2000/Win 98)

- Start -> Run -> type cmd

At the command prompt, type:


ipconfig /flushdns

Certain Linux distributions

- Restart the nscd daemon by typing /etc/rc.d/init.d/nscd restart in your terminal using root credentials.

Mac OS X (10.4 and under)

- type lookupd -flushcache in your terminal to flush the DNS resolver cache.

Mac OS X (10.5 up to 10.7)

- type dscacheutil -flushcache in your terminal to flush the DNS resolver cache.

Mac OS X (10.7 and 10.8)

- type sudo killall -HUP mDNSResponder in your terminal to flush the DNS resolver cache.

Resources