Dns

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DNS is the Domain Name System, a global co-ordinated, distributed database which maps zones to IPs on the The Public Internet.

DNS records are used to translate human readable names such as vistua.com and www.google.com into machine readable addressing codes called IP addresses or IP numbers, IP numbers take forms like this 64.152.153.23. This is why some machines have names, for example the machine frontios.vistua.net in the Vistua intranet?.

The DNS root zone is a single dot (.), similar to the file system root / on UNIX. Unlike UNIX filesystem paths, though, DNS zones are organized from right to left, the single dot is rarely used outside of engineering contexts because all software is to assume its presence except when so doing would cause ambiguity (such as in the aforementioned engineering situations). The root zone is administered by ICANN under license from the U.S. Department of Commerce which thus controls the Internet DNS scheme.

Individual persons and organizations then register domains under a TLD, "Top Level Domain" of . examples include .com and .uk, note that technically in this is .com. and .uk. because of that root zone which is usually omitted. Most countries have a ccTLD, or Country-Code TLD, which is assigned based on the ISO Country Code for that nation, for example Switzerland's ccTLD is .ch and the United State's is .us.

Many of these ccTLDs allow direct registrations only under "second level" domains such as .co.uk and .com.au, others do not, for instance the Vistua Network could register vistua.ch for it's Swiss division (if it had one) but could not register vistua.au for its purported Australian division, it would have to register vistua.com.au or vistua.net.au or something like that instead.

Domains are provisioned by registering them in the DNS system which is a function provided by registrars, which are commercial entities and charge for this service, although it is usually inexpensive. Vistua's registar is the Canadian company EasyDNS. The exceptions to this rule are .mil and .gov which are the military and civilian government TLDs for the U.S. Government (other countries use their ccTLD, or a second level domain of it such as .gob.mx for instance in Mexico and .govu.fr in France.) .gov registrations are handled by the Government Services Administration and .mil is handled by the Defence Information System Agency DISA.

It is possible to look up domains IP numbers manually by using the UNIX command nslookup, and to retrieve other types of DNS records (such as MX records which route email) using the UNIX dig command. The whois command can be used on UNIX to obtain information about the registrant of a domain.

In-spite of anxiety about the status of the DNS root zone no one has been able to propose an alternative system that would be better.

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