about domains

[linux]

Hi guys . I understand what DNS is for but not sure exactly how it works. Need someone to explain it a bit more. If I want to buy a .com domain name from say name.com does it include the DNS service and the the second question is if I buy from say domains.co.za vs say name.com will the physical location of the dns server be in south africa if I buy from domains.co.za. And if so will the people from the States then have a slower lookup response time or how does it work?

Regards.

 

[Johnatan56]

DNS servers don't have to know "all" domains. They only need to know who is "authoritative", which it learns from a set of "root" servers. Each DNS server has a list of "root" servers, and this list changes infrequently. On one of my DNS servers, there are 18 root servers configured, and this configuration came when I installed the DNS server two years ago, and if the list of root servers has changed since then, enough of them are accessible that I haven't noticed it.

My DNS server, when asked to resolve a domain it doesn't know, makes a query to a root server to find out what other DNS server is authoritative for the domain. The response it gets may contain additional "NS" records and be marked non-authoritative, in which case my DNS server knows that it has to "follow the chain" and make a new query to a new server. Eventually, it finds a DNS server that provides authoritative information, and queries can be made that are not just NS records. A (address) and MX (mail exchange) are of course the two most common.

https://superuser.com/questions/477314/how-do-dns-servers-work

The above is the best explanation I found, follow the link for the beginning/end. Basically the DNS server will just ask up the tree until it finds one that knows, if you typed a .co.za domain it will look at the main .co.za registrar.

 

[linux]

Thanks.
Understand it better now

 

[gkm]

Also, DNS does caching, so most people in SA will still get a fast response on a domain lookup for a .com domain, if other people on the same ISP has looked it up recently. Many DNS providers allow you to set for how long results will be cached.