Ka-Boom-Time for DNS

DNS-Domain Name Service.Google now introduced its public DNS.DNS is nothing but a resolver.It converts the URLs we type in the address bar of the browser into the ipaddress of the server to which the URLs we typed correspond.


Before I speak of Google DNS.Let me tell you the  how DNS actually works.Everyday an average user needs hundreds of DNS references.So in order to enhance the speed of getting the ipaddress from a DNS server,we use UDP at the trasport layer.
Communication in DNS server do not always involve only UDP.It involves TCP protocol too.Many of us donot know the reason that it used TCP protocol for communication.When the communication is between the Client browser and the DNS server,DNS uses UDP,coz there are millions of clients using the DNS service and so TCPs 3-way handshake will take a hell lot of time,but before we continue,reflect on this question.There are number of DNS servers all around the world.Suppose I own a site Langoota.com,I decide  to change the ipaddress of my site.So it means i need to change the entry in the DNS server right?As I told you,there are many DNS servers,I update the change(i.e the change of my server's ipaddress)  in one DNS,how will the other DNSs know about the change?
yea,The communication between the DNSs take place using TCP.i.e if a DNS server finds an entry in it has been modified,it has to update it to other servers right?This it does using TCP,coz it cannot afford to be careless,so that is the reason it uses reliable TCP 3-way hand shake.

Coming back to Google DNS,in order to make the web more faster,Google it self  came up with a public DNS.

Why Google DNS?What is the effect on the performence?

• Speed: Resolver-side cache misses are one of the primary contributors to sluggish DNS responses. Clever caching techniques can help increase the speed of these responses. Google Public DNS implements prefetching: before the TTL on a record expires, we refresh the record continuously, asychronously and independently of user requests for a large number of popular domains. This allows Google Public DNS to serve many DNS requests in the round trip time it takes a packet to travel to our servers and back.
• Security: DNS is vulnerable to spoofing attacks that can poison the cache of a nameserver and can route all its users to a malicious website. Until new protocols like DNSSEC get widely adopted, resolvers need to take additional measures to keep their caches secure. Google Public DNS makes it more difficult for attackers to spoof valid responses by randomizing the case of query names and including additional data in its DNS messages.
• Validity: Google Public DNS complies with the DNS standards and gives the user the exact response his or her computer expects without performing any blocking, filtering, or redirection that may hamper a user's browsing experience.
  

For guide on configuring your system to use  Google DNS click here. I am already using itIts faster.Try this out.Be careful while your are changing the DNS settings of your computer.

Half knowledge is dangerous.

Good Day!.