Learn Windows XP Professional in 15 Minutes a Week: Understanding DNS in Windows XP Professional Page 2

By ServerWatch Staff (Send Email)
Posted Oct 30, 2002


The following is an example of the query process of a client computer making a request to a DNS server to resolve the address web address of www.zandri.net.

First, the client computer generates a request for the IP address of www.zandri.net by sending a recursive query to the DNS server that it is configured to use in its network configuration. (We'll call this server LOCALCFG.)

The second step is for the LOCALCFG DNS server that has received a recursive query to look for the name in its local database. If it does find that answer locally, it is returned. If it is unable to locate an entry for www.zandri.net in its own database, it sends an iterative query to a DNS server that is authoritative for the root of the local domain. (We'll call this server LOCALROOT.)

If the LOCALROOT DNS server, which is authoritative for the root domain, has the answer in its local database, it sends a response to LOCALCFG. If the LOCALROOT DNS server is unable to locate an entry for www.zandri.net in its database, it sends a reply to the querying DNS server (LOCALCFG) with the IP addresses of DNS servers that are authoritative for the .net domain. (If it were .com you would be sent the IP addresses of DNS servers that are authoritative for the COM domain. If it were .org you would be sent the IP addresses of DNS servers that are authoritative for the ORG domain, and so on.) We'll call this server DNSNET.

The DNS server that received the client recursive query (LOCALCFG) sends an iterative query to a server that is authoritative for the .net domain (DNSNET). 

If the DNS server that is authoritative for the .net domain (DNSNET) has an entry for www.zandri.net in its local cache, it will return it to LOCALCFG. If DNSNET is unable to locate an entry for www.zandri.net in its database, it will send a reply to the querying DNS server (LOCALCFG) with the IP addresses of DNS servers that are authoritative for the zandri.net domain. (We'll call this server ZANDRIDNS.)

The DNS server that received the client recursive query (LOCALCFG) sends an iterative query to a server that is authoritative for the zandri.net domain (ZANDRIDNS).

The DNS server that is authoritative for the zandri.net domain (ZANDRIDNS) locates an entry for www.zandri.net in its database and sends a reply to the querying DNS server (LOCALCFG) with the IP address of www.zandri.net.

Finally, the DNS server (LOCALCFG) that received the recursive query sends a reply to the client computer with the IP address of www.zandri.net.

Well, that wraps up this section of "Learn Windows XP Professional in 15 Minutes a Week." I hope you found it informative and will return for the next installment.

As always, if you have any questions, comments or even constructive criticism, please feel free to drop me a note. I want to write solid technical articles that appeal to a large range of readers and skill levels, and I can only be sure of that through your feedback.

Until next time, best of luck in your studies and remember,


"Clones are people two."


Jason Zandri
www.2000trainers.com


Page 2 of 2


Comment and Contribute

Your name/nickname

Your email

(Maximum characters: 1200). You have characters left.