History of the DNS

Hi Everyone,

Im working in the one of the biggest data centers in USA

as a system administrator and always have people asking me about Internet

in a real live. Their big misunderstanding place is exactly about the hostname

resoving, they cannot understand how IP could be attached to a hostname

and thatswhy most people associate Internet with webpages, what is

definately not right. I will try to explain here in short what is DNS. This

will allow people to have more deep understanding about Interner.

Litte bit of history:[/b]

The practice of using a name as a more human-legible abstraction of a

machine’'s numerical address on the network predates even url=http://en.wikipedia.org/wiki/TCP/IPTCP/IP[/url], and

goes all the way back to the url=http://en.wikipedia.org/wiki/ARPAnetARPAnet[/url] era. Originally, each computer on the

network retrieved a file called HOSTS.TXT from SRI (now SRI International)

which mapped an address (such as to a name

(such as www.example.net.) The Hosts file still exists on most modern

operating systems, either by default or through configuration, and allows

users to specify an url=http://en.wikipedia.org/wiki/IP_addressIP[/url] address to use for a url=http://en.wikipedia.org/wiki/Hostnamehostname[/url] without checking the url=http://dns-server.buyregion.info/dns-server.htmlDNS server[/url].

This file now serves primarily for troubleshooting DNS errors or for mapping

local addresses to more organic names. (The Hosts file can also help in

ad-blocking, and url=http://en.wikipedia.org/wiki/Spywarespyware[/url] may utilize it to hijack a computer.) But a system

based on a HOSTS.TXT file had inherent limitations, because of the obvious

requirement that every time a given computer’'s address changed, every

computer that wanted to communicate with it would need an update to its

Hosts file.

DNS in the real world[/b]

Users generally do not communicate directly with a DNS resolver. Instead

DNS resolution takes place transparently in client applications such as web

browsers (like url=http://en.wikipedia.org/wiki/Internet_ExplorerInternet Explorer[/url], url=http://en.wikipedia.org/wiki/Opera_%28web_browser%29Opera[/url], url=http://en.wikipedia.org/wiki/Mozilla_FirefoxMozilla Firefox[/url], url=http://en.wikipedia.org/wiki/Safari_%28web_browser%29Safari[/url], url=http://en.wikipedia.org/wiki/Netscape_NavigatorNetscape Navigator[/url],

etc), mail clients (url=http://en.wikipedia.org/wiki/Outlook_ExpressOutlook Express[/url], url=http://en.wikipedia.org/wiki/Mozilla_ThunderbirdMozilla Thunderbird[/url], etc), and other Internet

applications. When a request is made which necessitates a url=http://dns-server.buyregion.info/dns-server-lookup.htmlDNS lookup[/url], such

programs send a resolution request to the local DNS resolver in the operating

system which in turn handles the communications required.

The DNS resolver will almost invariably have a cache containing recent

lookups. If the cache can provide the answer to the request, the resolver

will return the value in the cache to the program that made the request.

If the cache does not contain the answer, the resolver will send the request

to a designated DNS server or servers. In the case of most home users,

the url=http://en.wikipedia.org/wiki/Internet_service_providerInternet service provider[/url] to which the machine connects will usually

supply this url=http://dns-server.storage9.com/dns-server.htmlDNS server[/url]: such a user will either configure that server’'s

address manually or allow url=http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_ProtocolDHCP[/url] to set it; however, where systems

administrators have configured systems to use their own url=http://dns-server.nspider.co.uk/dns-servers-list.htmlDNS servers[/url],

their DNS resolvers will generally point to their own nameservers. This

name server will then follow the process outlined above in DNS in theory,

until it either successfully finds a result, or does not. It then returns its

results to the DNS resolver; assuming it has found a result, the resolver

duly caches that result for future use, and hands the result back to the

software which initiated the request.

Types of DNS records[/b]

Important categories of data stored in the DNS include the following:

*An A[/b] record or address record maps a hostname to a 32-bit

url=http://en.wikipedia.org/wiki/IPv4IPv4[/url] address.

  • An url=http://en.wikipedia.org/wiki/AAAA_recordAAAA[/url] record or url=http://en.wikipedia.org/wiki/IPv6IPv6[/url] address record maps a hostname

to a 128-bit IPv6 address.

  • A CNAME[/b] record or url=http://en.wikipedia.org/wiki/Canonical_namecanonical name[/url] record makes one domain

name an alias of another. The aliased domain gets all the subdomains

and DNS records of the original.

  • An url=http://en.wikipedia.org/wiki/MX_recordMX[/url] record or mail exchange record maps a domain name to

a list of mail exchange servers for that domain.

  • A PTR[/b] record or pointer record maps an IPv4 address to the

url=http://en.wikipedia.org/wiki/Canonical_namecanonical name[/url] for that host. Setting up a PTR record for a hostname

in the in-addr.arpa domain that corresponds to an IP address implements

reverse url=http://dns-server.od0.info/dns-lookup-server.htmlDNS lookup[/url] for that address. For example (at the time of writing),

www.icann.net has the IP address, but a PTR record maps to its canonical name, referrals.icann.org.

  • An NS[/b] record or name server record maps a domain name to a list

of DNS servers authoritative for that domain. Delegations depend on

NS records.

  • An SOA[/b] record or start of authority record specifies the DNS server

providing authoritative information about an Internet domain, the email of

the domain administrator, the domain serial number, and several timers

relating to refreshing the zone.

  • An url=http://en.wikipedia.org/wiki/SRV_recordSRV[/url] record is a generalized service location record.

  • A TXT[/b] record allows an administrator to insert arbitrary text into a

DNS record. For example, this record is used to implement the Sender

Policy Framework specification.

  • url=http://en.wikipedia.org/wiki/NAPTR_recordNAPTR[/url] records (NAPTR stands for “Naming Authority Pointer”) are

a newer type of DNS record that support regular expression based rewriting.


Many investigators have voiced criticism of the methods currently used to control

ownership of domains. Critics commonly claim abuse by monopolies or

near-monopolies, such as VeriSign, Inc. Particularly noteworthy was the

VeriSign Site Finder system which redirected all unregistered .com and .net

domains to a VeriSign webpage, this was rapidly removed after widespread critism.

There is also significant disquiet regarding United States political influence over

the Internet Corporation for Assigned Names and Numbers (ICANN). This was

a significant issue in the attempt to create a .xxx Top-level domain and sparked

greater interest in Alternative DNS roots that would be beyond the control of any

single country.

Information was combined by using different websites inluding url=http://en.wikipedia.org/Wikipedia[/url].

I hope this article help to understand DNS as well and assume internet is


Thank you for the patience.



so your question is not really a question, is it?

A much better place would be an external wiki for such a document as it has no direct relation to setting up Wildfire. So I wonder how useful it is. Users may be much interested about SRV records and the Wildfire domain name.