Page 18 - DCAP202_Fundamentals of Web Programming

Unit 1: Internet Basic

programs, i.e., Internet Explorer, Netscape, Outlook, etc. to use this address when communicating Notes
with other hosts. The seventh layer in the OSI model has the IP addresses.
The MAC address is a hardware address, which means it is unique to the network card installed
on your PC. No two devices on a local network should ever have the same MAC address. In the
unlikely event this occurs, the two devices will have major communication problems. During
the manufacturing process, the vendor “burns” a specific MAC address into each network card’s
ROM. When the serial numbers have all been used, they start from the beginning, as it’s very
unlikely anyone would buy two network cards from the same vendor, and they will contain the
same MAC address.

Notes You should remember that a IP address is a logical address which is configured via
the operating system, while the MAC address is a hardware address, burnt into the network
card’s ROM during the manufacturing process.

1.6.5 Static Vs Dynamic IP Address

An IP address can be static or dynamic.
A static IP address will never change and it is a permanent Internet address.
A dynamic IP address is a temporary address that is assigned each time a computer or device
accesses the Internet.

Task Compare static and dynamic IP address.
Self Assessment

Fill in the blanks:
12. An ........................... is an identifier for a computer or device on a TCP/IP network.
13. A ........................... is the standard hostname given to the address assigned to the loopback
network interface.
1.7 TCP/IP (Transmission Control Protocol/Internet Protocol)

TCP/IP is made up of two acronyms, TCP, for Transmission Control Protocol, and IP, for Internet
Protocol. TCP handles packet flow between systems and IP handles the routing of packets.

All modern networks are now designed using a layered approach. Each layer presents a predefined
interface to the layer above it. By doing so, a modular design can be developed so as to minimize
problems in the development of new applications or in adding new interfaces.

1.7.1 TCP/IP Protocol Architecture

The ISO/OSI protocol with seven layers is the usual reference model. Since TCP/IP was designed
before the ISO model was developed it has four layers; however the differences between the two
are mostly minor. Below, is a comparison of the TCP/IP and OSI protocol stacks:
OSI Protocol Stack

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