If you are using BSNL as your internet service provider, the chances are more that you might be frequently encountering error similar to “DNS error – cannot find server“. Usually this error occurs when you try to access some websites. However, some other sites may work properly without any issues. Atleast I encountered this issue today for almost 6 hours before I could figure out what was going wrong. When I called up BSNL customer care on 1957, they acknowledged some problems with their DNS Servers and did not have any other details on how to solve except to wait and try after some more time. I recalled that a similar issue being much discussed on our office internal mailing list a couple of weeks back. Looking up on that mail thread gave me the solution to this problem.
The solution is very simple and all you need to do is – configure your network adapter to point to OpenDNS instead of BSNL DNS ip addresses. Set the the ip addresses 18.104.22.168 and 22.214.171.124 as preferred and alternate DNS entries respectively. More detailed information on how to set it up for various operating systems has been provided on OpenDNS site. As per the info on their site, it helps to surf the Internet faster, smarter, safer and more reliably than ever before. OpenDNS operates as the largest and most intelligent DNS caches in the world, it is also said to have 100% up time DNS network.
So, if you have a similar issue with other internet service providers as well, go ahead and change the DNS entries to point to OpenDNS and everything should start working. Now I am able to access all the sites without any errors! Thanks OpenDNS :)
Update: Looks like there is a massive disruption in the net connection as well due to submarine cables breakdown between Egypt and Italy. More info here from Times Of India.