In the past week or so, I’ve had five readers advise me that one or more of the links on this site weren’t working (this issue crops up occasionally). One reader pointed out, that on his desktop machine he had issues with a particular link – but on his laptop, the link worked fine.
Since I use CoolPreviews (a free application I highly recommend), to establish that article links are working before I post – as illustrated below – when I get this particular query, I’m reasonably sure that what we’ve got here is a “failure to communicate” (thank you Cool Hand Luke), caused by an issue with the reader’s DNS cache.
If you’ve encountered similar problems here, or elsewhere – or problems with an unusually high number of Not Found 404 error codes while surfing, it’s probable that you need to flush your DNS cache.
Here’s why – From LCN:
DNS caching is a double-edged sword. It speeds up resolution by storing recent answers, and short-circuiting the normal resolution process. However there is a down side. Because DNS servers cache answers, and don’t delete these answers until the time to live (ttl) expires, it can take hours or days for the entire Internet to recognize changes to DNS information for your domain name.
Clearing your DNS cache forces your machine to query DNS name servers for updated DNS information.
Here are two ways in which you can clear your DNS cache:
The Geek way:
Go to “Run” in the Start menu (“Search” for “Run” if you can’t see it).
In the Run box, type CMD (doesn’t need to be capitalized).
At the command prompt, (not in the Run box), type – ipconfig/flushdns.
Hit “Enter”, and that’s it. Your DNS cache has just been flushed.
The less Geeky way (the easy way):
Install and run CCleaner – it’s free, and it’s really a “must have” for all computer users.
CCleaner will allow you to flush your DNS cache by simply checking the appropriate box – as illustrated below.
My DNS cache is partially illustrated below before flushing with CCleaner. You can see what’s in your DNS cache by entering ipconfig/displaydns at the command prompt.
DNS cache after flushing with CCleaner.
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