You might be using a default DNS (Domain Name Server) from your ISP or may be OpenDNS or UltraDNS. But they might not be fast enough for you. These softwares will help you find the fastest DNS servers to use and test their speeds.
Namebench is the software to find the best and fastest DNS server for you with deep testing and provide the result to you in html file. And it works in Linux, Mac and Windows.
Just download Namebench in the download section from Google Code. All you have to do now is to run the program. It will test the free DNS services like OpenDNS, Google Public DNS, and UltraDNS and some Servers near you to find you the best DNS services. And will give you detailed report on the results on which to use.
The namebench window looks like this.

And the recommendation
The 192.168.1.1 is the ip for my router so the others are the external DNS which you use to access internet.
The other is DNSBench. This too checks for the fastest DNS server you can use. Its little faster than namebench and gives you more information on DNS servers for you to choose.
Now you can choose the best DNS server for faster internet access. You don’t have to depend on the ones that are slow. Use the fastest servers ip in the properties section of your Connection on Network Connections.
You will be having faster domain resolution and with much better internet browsing experiences with the suggested fast DNS services.
Thank you very much! It helps me a lot, this can also resolve “destination net unreachable” problem? thank you and god bless!!
We are happy we could help. 🙂