what is the use of DNS?

Question

I can browse internet from office even without gving DNS entry in IP address. Then what exactly DNS is doing. I have a proxy server. So when ever I give yahoo.com it is resolving the name even when i remove dns entry from my PC. then y use DNS? Help me...........

Answer 1

you shurely use dns.



if you do not use it in a more direct way, you use it indirectly



dns can be autodiscovered if you have not set it manually.



as you said, you have a proxy server through which you exit outside.



let`s have t this way: if dns servers were not invented, today we weill still have to enter ip addresses to connect to yahoo, hotmail, msn, intel, and, microsoft, apple and so on... [to their webpages i ment, but you figured it]



if you exit through a proxy, you will only have to redirect your computer`s requests to that proxy. the proxy itself has the dns setup or it autodiscovered it.



the reason you might need to set up a dns behind a proxy server is because your local network might have a few webservers which provide services.



that is all.



ps for intrested dude: the dns cache is kept 360 minutes. at most.

Answer 2

DNS is the one who converts NAMES (www.yahoo.com) to IP ADDRESS (209.191.xxx.xxx).



you will be able to browse the internet even if you do not set the DNS address manually because something (ROUTER or SERVER) in your office is giving your computer a DNS automatically..



try to think of ANY ip address and put it in your PRIMARY and SECONDARY DNS and it will not work, because those IP ADDRESS there should be an IP ADDRESS of a DNS SERVER.

Answer 3

Your computer retains a cache of dns entries to avoid recursive look ups, therefore you can do without dns for a short while unless you ask to go somewhere, you have not been before.

Answer 4

if you didn't set the DNS addresses, your server will take them automatically from your ISP, cause it needs them to resolve website names to IP addresses