CONFIGURING AND TROUBLESHOOTING TCP/IPON A TCP/IP NETWORK, EACH DEVICE (COMPUTER, ROUTER, OR OTHER DEVICE WITH A CONNEC-TION TO THE NETWORK) IS REFERRED TO AS A HOST

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Lesson 1: Configuring and Troubleshooting TCP/IP

On a TCP/IP network, each device (computer, router, or other device with a connec-

tion to the network) is referred to as a host. Each TCP/IP host is identified by a logical

IP address that identifies a computer’s location on the network in much the same way

as a street address identifies a house on a street. Microsoft’s implementation of TCP/IP

enables a TCP/IP host to use a static Internet Protocol (IP) address or to obtain an IP

address automatically from a Dynamic Host Configuration Protocol (DHCP) server.

For simple network configurations based on local area networks (LANs), Windows XP

also supports automatic assignment of IP addresses. Windows XP Professional includes

many tools that you can use to troubleshoot TCP/IP and test connectivity.

After this lesson, you will be able to■ Explain the use of IP addresses.■ Configure TCP/IP to use a static IP address.■ Configure TCP/IP to obtain an IP address automatically.■ Explain the use of Automatic Private IP Addressing.■ Specify an alternate TCP/IP configuration for a computer running Windows XP Profes-sional.■ Use TCP/IP tools to troubleshoot a connection.Estimated lesson time: 60 minutes

What Is an IP Address?

Every interface on a TCP/IP network is given a unique IP address that identifies it on

that network. IP handles this addressing, defining how the addresses are constructed

and how packets are routed using those addresses.

An IP address consists of a set of four numbers, each of which can range from 0 to 255.

Each of these numbers is separated from the others by a decimal point, so a typical IP

address in decimal form might look something like 192.168.1.102. The reason that each

number ranges only up to 255 is that each number is actually based on a binary octet,

or an eight-digit binary number. The IP address 192.168.1.102 represented in binary

form is 11000000 10101000 00000001 01100110. Computers work with the binary for-

mat, but it is much easier for people to work with the decimal representation.

An IP address consists of two distinct portions:

■

The network ID is a portion of the IP address starting from the left that identifies

the network segment on which a host is located. Using the example 192.168.1.102,

the portion 192.168.1 might be the network ID. When representing a network ID,

it is customary to fill in the missing octets with zeroes. So, the proper network ID

would be 192.168.1.0.