CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

3.2. The TCP/IP Protocol

Since the dramatic growth of the Internet, TCP/IP has become the preferred protocol on networks today. TCP/IP is the common protocol on all desktops — including Windows, Linux, and Macintosh systems — allowing all these different OSes to communicate over a common protocol. It doesn't matter what OS you run or what kind of network you have: As long as you are running a common protocol such as TCP/IP, you can access resources across any platform.

TCP/IP is installed by default with every major OS (Windows, Mac OS X, and Linux). When configuring TCP/IP on these systems, three major settings need to be configured to allow the computer to communicate with other computers on different networks or the Internet:

• IP address

• Subnet mask

• Default gateway

To troubleshoot communication across TCP/IP, you need to understand the types of settings that need configuring. In the sections that follow, you look at how to configure TCP/IP and at some utilities to help you troubleshoot the protocol.

3.2.1. IP address

The IP address is a 32-bit number that is unique to your computer. No two systems can have the same IP address. An IP address is similar to the address of your home, which is the method by which other people send mail to you. An IP address works the same way on a TCP/IP network: You will assign the number to your computer, and it is the method other computers use to send information to your computer.

An IP address is made up of four sets of numbers separated by periods: ...