Something about IP addresses, the phone-numbers of the Internet

This is a simplified introduction to beginners trying to explain the basics of Internet addressing. To identify all computers on the Internet, each computer is given it's unique address. Presently this has the form of 4 numbers between 0 and 265 separated by periods. The system allows addresses in the range 0.0.0.0 to 256.256.256.256. Even if a web-site has a name, like www.thomashoven.com for this one, it is on a server connected to the Internet, and this server has one or more unique IP-addresses. Analogy with phones: www.thomashoven.com is the name, and the IP address of the server it resides on is it's phone-number. Luckily, computers keep track of the IP addresses, so we don't have to relate to those. When you dial up to connect your computer to the Internet, the server it connects to will give your computer it's own unique IP address that you will have for the duration of your online session.

The organization that has the worldwide responsimility to allocate IP addresses is called IANA (Internet Assigned Numbers Authority). The world is divided in four (soon to become five - a separate one for Africa) sections, each with responsibility of their own allocated block of IP addresses. To quote IANA: "The IANA maintains a high-level registry of IP addresses. It works with the Regional Internet Registries (RIRs) to distribute the large blocks of IP addresses among the RIRs. There are currently 4 RIRs, distributed around the world: APNIC (Asia/Pacific Region), ARIN (North America and Sub-Sahara Africa), LACNIC (Latin America and some Caribbean Islands), and RIPE NCC (Europe, the Middle East, Central Asia, and African countries located north of the equator). (A fifth regional registry is in formation for Africa.)"These four places are where you should look if you want to find out who owns the machine for which a specific IP address is allocated: Each of these have an easily identifiable "WHOIS" window where you can enter the IP address you wish to investigate. Try one after the other until successful.

For Asia/Pacific region: APNIC

For North America and Sub-Sahara Africa: ARIN

For Latin America and some Caribbean Islands: LACNIC

For Europe, the Middle East, Central Asia, and above-Sahara Africa: RIPE NCC

It is possible to find the origin server (and who owns it) of any e-mail or web-site using these services, provided you are using a suitable e-mail software or browser. If your browser, like Microsoft Internet Explorer, cannot show this, there are various utilities on the internet that can help, like Network Tools. Sites like Register can find information about who owns a domain name. Note that there are a few DON'T DO's:

1. NEVER contact IANA or the Regional Internet Registries about complaints about content received from an IP address. This should be discussed with the owner of the server at that address.

2. Before shooting at the owner of a server (they often provide a special e-mail address where you can report abuses etc) consider the possibility that the owner may not know, or that many of todays viruses uses security glitches in e-mail software (particularly those from Microsoft) to re-distribute themselves without the owner of the system knowing it.

3. A smart idea, however, is to DO a check on the location of a server or owner of a domain name before revealing those credit card details during a purchase. It may be difficult to make legal proceedings in a small island state far away or in a 3rd world country.

For more technical description of IP addresses, see these IANA pages

(c) Thomas Høven 2004