RFC 1035

RFC 1035 is the modern specifications of Domain Name Service, or DNS. This document was published in November 1987, as a replacement of three other RFCs. The Domain Name Service was created to provide users with an easier system of locating addresses over networks. This document provides an overview of the implementation of the service and then drills down into the specifications of how Domain Name Service operates on a network. The following is a brief review of this RFC documentation.

The basic process of the DNS is to convert domain name, such as a web address, into an IP address. Let’s begin the process at a client node. The client node starts with the basic knowledge of one DNS server. This server is in the configuration that client receives when being assigned an IP address by the DHCP server. When the user requests a domain, for example a web address, the client node looks up the IP address from the DNS server that it has been assigned. If that DNS server cannot resolve the name and address, it passes the request onto the next DNS server. This process continues until either a localized DNS server can resolve the name or the request reaches the Master Domain Name Servers. There are currently 13 of these servers around the world. Once the IP address is resolved, it is sent back to the client node, and further communication can take place.

One of the most important activities that these DNS servers can perform is name caching. When a request is returned from the Master Domain Name Servers, it passes back through each of the preliminary DNS servers. Each one of these servers records the name to IP address link in its own cache. If another client requests the same domain name, the request will be resolved at the initial DNS server, and not have to be forward to the top level domains.
Within a DNS server entry, there are several different types of records. The most important of these are A, NS, CNAME, SOA, PTR, and MX. Each of these serves a different function. For example, the MX type is for mail exchange. This entry holds commonly used addresses that are used for email servers. When an email is sent, the DNS server looks for this entry. If one is not found, it uses the resolution process as described above to determine the location of the destination server.

Personally, DNS is one the best developments that has been made. Think about it, if DNS had not been developed, we would have to memorize IP addresses to surf the internet. It would not make it as much fun.

If the client machine is running Windows, there is a way to clear the DNS locally in case of corruption. If the user brings up a command prompt, using the command IPCONFIG /flushdns will clear the local DNS cache. The client machine will then start rebuilding its cache automatically as the machine is being used.

Mockapetris, P. (November 1987). "DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION." Retrieved August 19, 2009, from http://www.ietf.org/rfc/rfc1035.txt?number=1035