How to decide on the best alternative DNS serversfor the fastest web possible

[alexatkin]

I realised during my recent issues with Google DNS on Origin that it might be useful to mention how I originally came to the conclusion to stick with Google DNS rather than use something else.

There is a VERY useful Open Source DNS test application called NameBench which I used to decide on that.

Basically what it does is retrieve a database of known public DNS servers, work out which are near enough to you to be worth trying, runs various tests on them to determine if they are retrieving accurate information/are responding quick enough to be worth testing further, and then finally decide on 11 to test to see which are the quickest at getting the result.

It can then test DNS lookups based on various criteria such as your browser history or the top 250 websites from the popularity monitoring site Alexa, so you get a good idea of which server is fastest for your own usage pattern.

Why do you need to test at all? Each ISP has its own set of routes to get to servers on the Internet and may differ in performance between peak time and off peak. So while Google DNS might be faster on my ISP, OpenDNS might be faster on yours, both might suck at peak times. This way the results are entirely accurate for your own connection, not guess work based on what is popular.

The only down side is it takes several minutes to complete the tests and its better if you do not use your connection during that time to ensure it doesn't lag some of the tests more than others creating false results.

The important thing to note is to put your ISPs DNS servers in the box so it tests against those, as they "theoretically" should be the quickest for your connection. Leaving your router as the default DNS may give false results as your router might have cached some of the domains already, making it appear quicker. Its also a good idea to do the test at peak time so you know which server works the best when the Internet is busy as that could be VERY different to off peak hours.

Another interesting side effect is that it also shows how having DNS caching on your router DOES help. I see an average DNS lookup speed of 34ms but a minimum of 0.6ms, far quicker than could ever happen without local caching.