IP address

An Internet protocol or IP address is a four digit base 256 number. That is, four numbers of the range 0-255 in a hierarchy. It represents a particular host for services on the Internet. It is usually written with the digits in base 10 (ordinary decimal form) separated by dots/periods. For example:

The special or reflexive address or localhost is always used only to mean this host, the one on which the code executes. In a totally protocol-based architecture this is very significant, as services will prefer to migrate to a host closer to the eventual end user and ideally to execute privately on their terminal - even a small one such as a worn device. This enables among other things Very Personal Computer services to handle very sensitive data like biometrics, biofeedback or PIMs.

Similarly, the digit 255 is not used to specify any particular address but an IP gateway to all the addresses in that range (similar to the use of minus one as a flag). When an asterisk is used instead, as in 25.234.*.*, it specifies a /256 mask.

When specifying masks in code the notation /16, as in meaning the 16 IP numbers in which localhost operates, is more common. These notations are very important in hard security and the prevention of malware and spying.

types of connections


A static IP address is one assigned by a host to a computer using a cable modem, DSL modem or direct Ethernet connection. Some networks make it easy to change IP addresses - holding easily broken IP leases - but many do not. Static addresses are required for web hosting so that domain names look up very reliably. Changing the address of a web host may take days to propagate through DNS services.


A dialup IP address, one assigned by a host to a computer using a modem on plain copper wire, typically is assigned in a B range of 65K addresses, e.g. 25.234.*.*

These are reassigned with every dialup event and so are quite hard to track. Even when they use static Internet connections, anonymous trolls use web proxy services running on dialup IPs.


A need for more IP addresses prompted Internet2, a project that also has many implications for Internet Governance.