The Nslookup of Linux commands

Http://www.computerhope.com/unix/unslooku.htm

About Nslookup

The nslookup command is used to query Internet name servers interactively for information.

Overview

nslookup, which stands for "name Server Lookup", was a useful tool for finding out information about a named Domai N.

By default, nslookup would translate a domain name to an IP address (or vice versa). For instance, to find out what the IP address of microsoft.com are, you could run the command:

nslookup microsoft.com

... and you would receive a response like this:

Server:     8.8.8.8Address:    8.8.8.8#53non-authoritative answer:name:    microsoft.comaddress: 134.170.185.46Name:    microsoft.comaddress:134.170.188.221

Here, 8.8.8.8 are the address of our system ' s Domain Name Server. This is the server we are configured to, translate domain names into IP addresses. "#53" indicates that we were communicating with it on Port, which was the standard port number domain name serve RS use to accept queries.

below this, we had our lookup information for  microsoft.com . Our name server returned entries,  134.170.185.46  and  134.170.188.221 . This indicates, microsoft.com  uses a round robin setup to distribute server load. When you access micrsoft.com , you are directed to either of these servers and YOUR PACKETS WI ll berouted to the correct destination.

You can see the We have the received a "non-authoritative answer" to our query. An answer are "authoritative" only if our DNS have the complete zone file information for the domain in question. More often, our DNS would have a cache of information representing the last authoritative answer it received when it made a Similar query; This information is passed the server qualifies it as "non-authoritative": The information was recently rec Eived from a authoritative source, but the DNS server was not itself that authority.

The Nslookup of Linux commands