In a TCP/IP-based LAN, PCs use Internet Protocol (IP) addresses to identify each other. These addresses allow
computers that are attached to the network to locate each other. An IP
address is a 32-bit binary number. This binary number is divided into
four groups of eight bits known as "octets," each of which
is represented by a decimal number in the range of 0 to 255. The
octets are separated by decimal points. The combination 190.100.5.54
is an example of an IP address. This type of address is described as a
dotted decimal representation. Each device on the network that has an
IP address is known as a "host" or "node".
A secondary dotted decimal number, known as the subnet mask,
always accompanies an IP address. The dotted decimal number
255.255.0.0 is a subnet mask. The subnet mask is used by network
computers to determine whether a particular host IP address is
local (on the same network segment) or remote (on another
segment).
There are several options for assigning IP addresses for hosts
on a LAN:
- Manually assigned by the network administrator.
- Assigned by a DHCP server. (DHCP servers are discussed in the
next section.)
If there are more than a few computers, manually configuring
TCP/IP addresses for every host on the network can be a time
consuming process. This also requires that the network
administrator who is assigning the address understands IP
addressing and knows how to choose a valid address for the
particular network. The IP address that is entered is unique for
each host and resides in the computer driver software for the NIC.
This is opposed to the MAC address, which resides on the NIC
hardware. TCP/IP addressing will be taught in later courses.
The IP address is manually entered on the operating system
TCP/IP Properties Dialog Box on the Windows operating system
screen. There is a set of address settings or configurations that
are entered into the host machine TCP/IP dialog box:
- An IP address
- A subnet mask
- Default gateway address
- Optional values including a Domain Name System
(DNS) server
address
The default gateway address, Domain Name System, and DHCP are
discussed later in the chapter.
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Lab
Activity (PDF, 17 KB) |
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In this exercise, students will install a Network
Interface Card into a PC. Students will also
configure that NIC to use an IP address. |
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