Web Hosting Talk : Web Hosting Main Forums : VPS Hosting : Explain to me how this thing works please?

[sg552]

Hello,

I have a question. When client signup for hosting the hoster will usually provide 2 nameserver. Let's call it ns1.example.com and ns2.example.com

Client have a domain with namecheap.com - a domain registrar. He/she then will pasted the 2 nameserver under his domain section and then he add domain name to cpanel. After that the domain will propagate to his/her new website.

My question is how do the registrar know the IP of the webhost provider server? Please take a look at an example below:

Retrieving DNS records for see-why.net...

DNS servers
ns1.stablehost.com [72.249.127.244]
ns2.stablehost.com [173.255.220.131]

Answer records
see-why.net		MX	
preference:	0
exchange:	see-why.net
	14400s
see-why.net		SOA	
server:	ns1.stablehost.com
email:	cpanel @ stablehost . com
serial:	2011022801
refresh:	86400
retry:	7200
expire:	3600000
minimum ttl:	86400
	86400s
see-why.net		NS	ns1.stablehost.com	86400s
see-why.net		NS	ns2.stablehost.com	86400s
see-why.net		A	199.96.156.104	14400s

Authority records

Additional records
see-why.net		A	199.96.156.104	14400s

So as you can see the webhost got failover nameserver (2 different IP) and the client website is hosted elsewhere not on the same server as nameserver. I try to dig the 2 nameserver but no data is found to point/direct me to 199.96.156.104

I hope you could understand my question. How do the registrar know by just the 2 nameserver without client adding his/her website IP (199.96.156.104) to the registrar control panel?

Thanks in advance. Any reply is appreciated. Thank you

[manhalab]

The DNS resolution flow from local machine to server goes in the following manner,

Local machine >> local host file in local machine >> ISP nameservers >> root nameservers >> .com or .net or etc (root nameservers) >> hosted server

---------------


Now whenever you register a domain under a registrar they provide you with default nameservers that is to be used for the domain.

In the above example:

domain: see-why.net
nameservers: ns1.stablehost.com, ns2.stablehost.com

If you host the domain at the same place as nameservers then you can use stablehost.com nameservers for the domain.

However if you create the domain at another host , that hosting company will tell you to register the domain (see-why.net) with their nameserver

Eg: if you register at stablehost.com (registrar) but host site at godaddy, then you need to update the nameservers at stablehost.com with that of godaddy.


===============

"Client have a domain with namecheap.com - a domain registrar. He/she then will pasted the 2 nameserver under his domain section and then he add domain name to cpanel. After that the domain will propagate to his/her new website"

Here how it works is you register domain see-why.net at namecheap.com. The default nameservers for the domain would be the namecheap nameservers (something like ns1.namecheap.com, ns2.namecheap.com)
.
But you don't host the site at namecheap.. lets say at GVO (Global Virtual Opportunities). Then what you need to do is at your registrar end (namecheap) you need to update the namesevers used at GVO (ns1.gvodns.com. ns2.gvodns.com) only then your site will resolve.

"how do the registrar know the IP of the webhost provider server?"

Therefore only by adding your hosting company nameservers to the registrar the registrar know the hosting server ip. (In fact if you think about it... the registrar do not need to know the hosting server ip as such .. it only need the nameservers (ip's) of the hosting company that have your site hosted so that anyone requesting for the domain queries the set nameserver at the registrar end to get the server ip where the domain is hosted.

Hope you are able to understand my explanation.

Regards
Manhal

[fshagan]

Originally Posted by sg552

Hello,

see-why.net A 199.96.156.104 14400s[/code]

So as you can see the webhost got failover nameserver (2 different IP) and the client website is hosted elsewhere not on the same server as nameserver. I try to dig the 2 nameserver but no data is found to point/direct me to 199.96.156.104

See that "A" record?

The name servers maintain "pointers" that tell a web browser or email program where to go to find the site. But not every name server has that "A" record; only your "ns1" and "ns2" name servers do.

You enter the domain name "see-why.net" in your browser. Your browser starts asking where the heck it is located, because it really needs the IP address, not the name of the site.

It starts with your local computer's HOSTS file, and then, if not found there, asks the next nearest name server on the Internet. That is usually your ISPs name server. If that name server doesn't know, it queries up the line, finally ending up at one of seven master name server computers. Somewhere along the line, one of the name servers will say "I don't know where that site is, but the authoritative name server for that site is at 'ns1.example.com' at IP xxx.xx.xx.xxx".

So the browser goes to that name server's IP address, and asks where the site is. That name server says "I have an A record right here that has the exact IP address! Go here!"

That "ns1" and "ns2" name server are the "authoritative name servers" for your site. Why not have your "A" record stored in each and every name server, so you don't have to go bouncing all over the Internet? Because of all that information you see in the name server record ... A records, CNAME records, MX records ... all of that information would have to be stored on each and every name server. That's thousands of times, all over the world.

Instead, each of the name servers simply points to the "authoritative name servers" where all the information is found. Because data transfers at nearly the speed of light, a distributed system like this makes sense.

[sg552]

@minhalab and fshagan I really appreciate your answers.

I need help with this on how I can achieve this. I have my own domain helloworld.com and dns server at IP 171.255.213.241. What I need to do is to point my subdomain (example: blog.helloworld.com) to other hosting provider (example: hostgator.com - IP example: 88.255.213.241) by just adding 2 hostgator.com nameserver to my DNS control panel without adding hostgator IP 88.255.213.241 (blog.helloworld.com)? How could I do this?

As for now I can achieve this by creating A records pointing to hostgator.com server IP 88.255.213.241 and add two nameserver from hostgator.com

I don't want to use IP. I prefer just adding nameserver from hostgator.com to my helloworld.com dns server control panel. The domain registrar have this function (just adding nameserver to domain control panel). I was wondering how could I do the same?

Thanks in advance.