Routing Information Protocol; Ip Addresses And The Internet - NETGEAR RT311 Reference Manual

Reference Guide for the Model RT311 and RT314 Internet Access Gateway Routers

Routing Information Protocol

One of the protocols used by a router to build and maintain a picture of the network is the Routing
Information Protocol (RIP). Using RIP, routers update one another periodically and check for
changes to be added to the routing table. The Model RT311 and RT314 routers support both the
older RIP-1 and the newer RIP-2 protocols. Among other improvements, RIP-2 supports subnet
and multicast protocols. RIP is not required for most home applications. You can contact IANA at
www.iana.org .

IP Addresses and the Internet

Because TCP/IP networks are interconnected widely across the world, every machine on the
Internet must have a unique address to make sure that transmitted data reaches the correct
destination. Blocks of addresses are assigned to organizations by the Internet Assigned Numbers
Authority (IANA). Individual users and small organizations may obtain their addresses either from
the IANA or from an Internet service provider (ISP).
The Internet Protocol (IP) uses a 32-bit address structure. The address is usually written in dot
notation (also called dotted-decimal notation), in which each group of eight bits is written in
decimal form, separated by decimal points. For example, the binary address:
11000011 00100010
is normally written as:
195.34.12.7
which is easier to remember and easier to enter into your computer.
In addition, the 32 bits of the address are subdivided into two parts. The first part of the address
identifies the network, and the second part identifies the host node or station on the network. The
dividing point may vary depending on the address range and the application.
There are five standard classes of IP addresses. These address classes have different ways of
determining the network and host sections of the address, allowing for different numbers of hosts
on a network. Each address type begins with a unique bit pattern, which is used by the TCP/IP
software to identify the address class. After the address class has been determined, the software
can correctly identify the host section of the address. The three main address classes are illustrated
in Figure 10-1, which shows the network and host sections of the address for each address type.
10-2
00001100 00000111
Networks and Routing Basics