Today I started my computer and found that internet is not working ? As usual, first thing I did was to find that what is the real cause of problem.
This means that I will try to verify if problem is between me and ISP or problem is with ISP and their uplink. But I was not able to do anything, though my internet appears to be connected but no communication was there. Then I pinged few of the gateway's of my ISP and found that link between me and ISP Is fine, so problem lies either at ISP or may be in DNS ?
Coincidently I had IP address of eTI saved somewhere, when I pinged, I found its working so it was confirmed that internet link is fine but problem is with DNS ie. in Domain name resolving. I know about Open DNS from quite a while as I have used it earlier so I now used OpenDNS to solve the problem.

What is IP, DNS ?

Before going further, lets talk what really happened , how and why ?
In short, whenever you open a website, you give its name to the browser but in real internet uses number based internet addresses ie. IP, for instance when you open http://www.etalkindia.com then your request is sent to your ISP DNS server which resolves the domain name to its IP then request is forwarded to that server real server  and you get what you asked for.  Domain Name Servers are there to make it easy for human to remember addresses.

What was the problem and why happened ?

By now you should have understood the concept of DNS, for me I think DNS server of my ISP was not working and hence I was not able to open any site as there was no mean to convert domain name to its relative IP address. I then simply used OpenDNS to resolve domain names for me.

What really is OpenDNS ?

That was small introduction to DNS system and now lets talk about OpenDNS service.
OpenDNS allow you to use their DNS instead of your ISP's which guarantees you to have most reliable Domain Name Servers available online. They have large cache and they are faster to resolve a domain name for you. Using OpenDNS is as easy as modifying some details of your network connection.

IP addresses of  OpenDNS are:

• 208.67.222.222
• 208.67.220.220

They have compiled a comprehensive documentation to use OpenDNS in your varied network environments.

Other Services Provided by OpenDNS

Apart of providing you fast and reliable DNS service they offer you various other facilities, you will need to create a free account there and after that you can have lots of interesting information as well facilities.

Blocking Adult Websites
OpenDNS give you facility to block adult website on network ie. filtering of website. After creation of network under account you can enable or disable Adult content on your network.

OpenDNS uses adult site data which is provided by St. Bernard's iGuard. iGuard is the 100% human-reviewed URL database from St. Bernard Software. iGuard analysts work around the clock reviewing URLs to ensure that every update includes the latest sites, accurately categorized.
Moreover, they provide you facility to block/ unblock websites on your wish.

Protection against Phishing
OpenDNS operates and uses PhishTank, the Web's most trusted source of phishing data. Even Yahoo uses same. It verifies that you get what you asked, many time spammer spoof websites, they appear to be original but are not in real hence  can ditch you by taking your sensitive information.

Support for Dynamic IPs
It also support dynamic ip addresses, it means if your network is not having static IP , then still you can use it.

Statistics of the usage
They also provide data of usage of their service, you can see how many domains were requested etc. Below is the list..
    *  Total DNS requests
    * Total unique domains requested
    * Total unique IPs making requests (of interest for larger networks)
    * Domains requested, in ranked order with domain-specific totals
          o Actionable. If you see an unwanted domain pop up in your Domains stats, you can block the domain right from the stats display.
    * Blocked Domains requested (individual domain blocks)
    * Request Types (A, MX, PTR, and more)

Providing Shortcuts for your favourite links
They also provide facility where you can specify shortcuts for your favourite sites, for instance if ie type eTI in browser then it will open http://www.etalkindia.com.
You can specify shortcuts by logging to your account at OpenDNS


Apart of the above there are few many other services like domain check, facility to for domain owners to have smooth transition of domain name servers etc.

You are welcome Kammy !