DNS records

Types of DNS records

On a previous post I said that there are some more information's rather than domain name and IP address in a DNS server. There are many records in a DNS server. Records are of 5 types, A, CNAME, NS, MX and PTR.

A              : Map host name to an IP address

eg. xyz.com.     A  123.23.12.3

CNAME  : This record points other domain to a host name which is in A record.

eg. ftp.xyz.com.         A  xyz.com

NS             : This record specifies the authoritative name server for the domain.

eg. xyz.com             NS       ns1.abc.com.

MX             : Specifies the mail server.

PTR            : This record is used for reverse DNS lookup.

You can refer this link to get more :) 

Some usefull online tools for viewing DNS records

1. dnsrecordviewer
2. MXtoolbox
3. whois
4. viewdns
5. ultratools
6. dnsstuff
7. ping
8. dnswatch
9. dns-record-viewer

Reverse and Forward DNS lookup

DNS lookup

In small terms I found that it is the process which is initiated by a device which is connected to a DNS server say your personal computer which you use at your home which is connected to the internet, when you type a website address in your web browser chrome, firefox or whatever, that domain name is sent to a DNS server to lookup its corresponding IP. Process of looking in a DNS server for particular IP or Domain name can be called as DNS lookup. There are 2 types of DNS lookup, Forward DNS lookup and Reverse DNS lookup.

Forward DNS lookup is the process of looking for an IP address of a specific domain name in a DNS server.
Reverse DNS lookup is the process of looking for a domain name of a specific IP address in a DNS server.

Some tools used for DNS lookup..

1. MXtoolbox.
2. dnsstuff

Introduction to DNS

A bit about DNS

What is DNS and Why is DNS?? Answer for these 2 questions may clear all the basic doubts regarding DNS. Domain Name System aka DNS is a system that translates the domain name or host name to an IP address. This system uses a database which contains several records to translate a domain or host name to an IP address. The records in that database contains the mapping information's. There are different types of records in it.This databases are stored in a dedicated server and those servers are known as DNS servers. This is what is DNS.. :).

Then the second part why is DNS?? Actually why there is a need for DNS?? Can you remember 216.58.220.46 instead of www.youtube.com or 31.13.79.246 instead of www.facebook.com? Then there is the answer for it. This is the need of DNS. Its a fact that humans can't remember such long numbers of different patterns. Use of phone-book to store contact details of different persons is a good example. Actually whats in it? Its is just mapping of name and pone number.Yes, like that there is only domain names and IP addresses (and some information's regarding it we will see about those things later) are present in a DNS database. DNS makes us easier to remember addresses of different websites easily. It is true that we are surfing on Internet without actually knowing about the IP address of any page or site. You may even don't know whats the IP of this page now you are looking at..:). Thus DNS plays a crucial role in Internet. That's all a bit about DNS you can surf on net for more or can ask me...:)