We need a specific location for our data to be sent on networking sites. The manner in which we write a letter with specific address, our computers utilizes a special number or characters that are distinct in order to send the information to chosen computer present in the network. This special identifier is termed as IP address for a given system. The internet service provider that deals with translation of domain names to or from IP addresses are defined as Domain Name System. In short form it is written as DNS and is an internet directory service. The principle job of DNS is translation of domain names into IP address i.e. providing a domain name to the given IP address. The advantage is instead of writing down long series of IP address number we can get access to the same sites by simply entering the correct domain name of that particular site. DNS also have hold on the email delivery of the system i.e. the current web browser will be unable to find the address of the requested website if the DNS is not interpreted by the operating system, which in turn enables the user to receive or send mails.
Now the DNS comprise of three primary components
1) DNS data / Resource Records
3) Internet Protocols (to obtain data from the servers)
In the DNS large number of the resource records are further divided into millions of files. We call this file as zones. This zone comes under authorized servers that primarily operates to answer queries on account of resource records present inside zones they have copies of. Then we have this catching server that receives the given information from various servers and then cache any replies. We observe that mostly name servers are authoritative for just few zones but in case of large name server, it is seen are authoritative for tens of thousands of zones.
The Internet IP address, at 32 bits, encodes 2^32 or 4,294,967,296 possibilities. Now we need to think of solution to build a directory for all these range of large numbers. For instance, the way our phone operators build directory on basis of location.
The solution is using hierarchy of simple, mnemonic names, called domain names. Instead of noting down 220.127.116.11, all I need to know is what is the host’s domain name. It is argued that the dots in a domain name coincides to the dots in the numeric address. But This is not true. The IP address comprised of three periods that in turn divides its four constituent bytes. But in case of domain name we encounter number of periods. The documentation for the DNS is given by RFC 1034 and RFC 1035. Also, we observed in case of mail delivery again DNS plays an vital role.
Paul Mockapetris is person responsible for giving us Domain name system ( DNS ) IN 1983. This in turn open doors for growth of internet system beyond its academic origins. The primary problem with respect to early internet system that in a single table on a single host (HOST.TXT) hold names to the address translation. He came up with concept of DNS making it possible for the user to associate given IP address with simple names This in turn revolutionize the internet making it attractive for daily use.
The DNS process is given as follows:
Firstly, client gives a DNS request by submitting hostname such as “newsite.com”.
The given request is then approved by the DNS resolver. After which suitable IP address is found for the given host which in turn is associated for finding accurate IP address for that hostname.
The resolver moves down the hierarchy to Top Level Domain (TLD) DNS servers down to the name server accountable for the given domain “newsite.com”.
After the resolver discovers the authoritative DNS the resolver finds the authoritative DNS name server for “newsite.com”, it receives the IP address and returns it to the DNS client. The DNS request is now resolved.
Thus, by using the accurate IP address the DNS client device can be authorized to the server
DNS Message Format
The way in which the DNS message reacts with each other in two ways i.e. queries and replies. They consist of following:
1) First is the header section composing of identifications, flags, total number of questions, and its corresponding answers, also include resource records and other number of additional resource records.
2) Secondly, the flag field that contains sections of one or four bits, message type, authorization o the name server, type of query, determination is the request truncated and the status.
3) Thirdly, we have the question section that includes the domain name and type of record being resolved.
4) And finally, the answer section that contains accounts for resource records.
We observe based on the present applications the operating ability of most managed DNS platforms are severely constraint.
DNS is capable to be more than just a routing mechanism bridging the hostnames with its IPs. In case of Advanced DNS, it is capable to deliver functions like:
Multi CDN – Out of different CDN’s, particular CDNs are dynamically selected to be given to each user and optimal experience
Global server load balancing -Its application is aiding in order to develop connections between various data centers present around the World.
Geographical Routing – Main application is establishing connections between users and the network resource by selecting one that is present geographically about the user.
Cloud Migration – The main function is data integration by supplying the platform with aid of copying or synchronizing data given at a big scale
Internet Traffic Management – The main principle is filter traffic intelligently with the help of data available about resource readiness, load and network conditions, thus in turn enhancing the current performance.
The next-generation DNS servers have an ability to filter traffic and selective route which in turn may improvise our networking experience.