NX-590E Internet Interface
21
IP
Abbreviation of Internet Protocol, pronounced as two separate letters. IP
specifies the format of packets, also called datagrams, and the addressing
scheme. Most networks combine IP with a higher-level protocol called
Transport Control Protocol (TCP), which establishes a virtual connection
between a destination and a source.
IP by itself is something like the postal system. It allows you to address a
package and drop it in the system, but there’s no direct link between you and
the recipient. TCP/IP, on the other hand, establishes a connection between
two hosts so that they can send messages back and forth for a period of time.
The current version of IP is IPv4. A new version, called IPv6 or IPng, is under
development.
IP ADDRESS An identifier for a computer or device on a TCP/IP network. Networks using
the TCP/IP protocol route messages based on the IP address of the
destination. The format of an IP address is a 32-bit numeric address written as
four numbers separated by periods. Each number can be zero to 255. For
example, 1.160.10.240 could be an IP address.
Within an isolated network, you can assign IP address at random as long as
each one is unique. However, connecting a private network to the Internet
requires using registered IP addresses (called Internet addresses) to avoid
duplicates.
The four numbers in an IP address are used in different ways to identify a
particular network and a host on that network. The InterNIC Registration
Service assigns Internet addresses from the following three classes.
Class A – supports 16 million hosts on each of 127 networks
Class B – supports 65,000 hosts on each of 16,000 networks
Class C – supports 254 hosts on each of 2 million networks
The number of unassigned Internet addresses is running out, so a new
classless scheme called CIDR is gradually replacing the system based on
classes A, B, and C and is tied to adoption of IPv6.
