D-Link DI-304 User Manual - Ip Addresses

DI-304/DI-304M ISDN Remote Router 

Appendix B – Basic IP Concepts 

This appendix describes some basic IP concepts, the TCP/IP addressing scheme and 

show how to assign IP Addresses.  

When setting up the router, you must make sure all ports to be utilized on the router 

have valid IP addresses. Even if you will not use the ISDN or WAN ports, you 

should, at the very least, make sure the LAN port is assigned a valid IP address. This 

is required for telnet, in-band SNMP management, and related functions such as 

“trap” handling and TFTP firmware download. 

IP Addresses 

The Internet Protocol (IP) was designed for routing data between network sites all 

over the world, and was later adapted to allow routing between networks (often 

referred to as “subnets”) within any site. IP includes a system by which a unique 

number can be assigned to each of the millions of networks and each of the 

computers on those networks. Such a number is called an IP address. 

To make IP addresses easy to understand, the originators of IP adopted a system of 

representation called “dotted decimal” or “dotted quad” notation. Below are 

examples of IP addresses written in this format: 

201.202.203.204        189.21.241.56        125.87.0.1 

Each of the four values in an IP address is the ordinary decimal (base 10) 

representation of a value that a computer can handle using eight “bits” (binary 

digits — 1s and 0s). The dots are simply convenient visual separators. 

Zeros are often used as placeholders in dotted decimal notation; 189.21.241.56 can 

therefore also appear as 189.021.241.056. 

IP networks are divided into three classes on the basis of size. A full IP address 

contains a network portion and a “host” (device) portion. The network and host 

portions of the address are different lengths for different classes of networks, as 

shown in the table below. 

87