Module 1 of the CCNA curriculum covers fundamental networking concepts including: 1) The physical and logical requirements for connecting a computer to the Internet using network interface cards or modems. 2) Binary number systems and how to convert between binary, decimal, and hexadecimal representations which is important for IP addressing. 3) Key networking technologies like TCP/IP, IP addressing, subnet masks, and how to represent and calculate network addresses from a device's IP and subnet mask.

1. CCNA – Semester1
Module 1
Introduction to Networking
Objectives
• Network physical connection
• Basic computer components
• Network math and IP address concept

2. Connecting to the Internet
Requirements for Internet Connection
• Connection to the Internet can be broken down into the
following:
– Physical connection: used to transfer signals between PCs within the
local network and to remote devices on the Internet
– Logical connection: uses standards called protocols. A protocol is a
formal description of a set of rules and conventions that govern how
devices on a network communicate.
– The application: interprets the data and displays the information in an
understandable form

3. Information flow
Case Study: Boot process
BIOS ROM RAM
OS HDD RAM
SHELL RAM IO
User Interface

4. Network Interface Cards
• A network interface card (NIC) is a printed circuit
board that provides network communication
capabilities to and from a personal computer
• When you select a network
card, consider the following
three factors:
– Type of network
– Type of media
– Type of system bus
Modem
• A modem, or modulator-
demodulator, is a device that
provides the computer with
connectivity to a telephone line.
• The modem converts (modulates)
the data from a digital signal to an
analog signal that is compatible
with a standard phone line.

5. NIC and Modem Installation
• Connectivity to the Internet
requires an adapter card,
which may be a modem or NIC.
• Notebook computers may have
a built-in interface or use a
PCMCIA card. Desktop
systems may use an internal
or external NIC.
High-Speed and Dialup Connectivity
• By the 1990s modems were running at 9600 bps and
reached the current standard of 56 kbps (56,000 bps) by
1998.
• High-speed services used in the corporate environment,
such as Digital Subscriber Line (DSL) and cable modem
access, moved to the consumer market.
• These services no longer required expensive equipment
or a second phone line. These are "always on" services
that provide instant access and do not require a
connection to be established for each session.

6. TCP/IP Description and Configuration
• Transmission Control
Protocol/Internet Protocol (TCP/IP)
is a set of protocols or rules
developed to allow cooperating
computers to share resources
across a network.
• To enable TCP/IP on the
workstation, it must be configured
using the operating system tools.
Testing Connectivity with Ping
• Ping is a program that is useful for verifying a
successful TCP/IP installation.
• It works by sending multiple packets to a
specified destination requesting for replies.

7. Ping Command
• ping 127.0.0.1 - This ping is unique and is called an internal
loopback test. It verifies the operation of the TCP/IP stack and NIC
transmit/receive function.
• ping IP address - A ping to a host PC verifies the TCP/IP address
configuration for the local host and connectivity to the host.
Web Browser and Plug-Ins
• Web browsers acts on behalf
of a user by
– Contacting a web server
– Requesting information
– Receiving information
– Displaying the results on a
screen
• Plug-ins is to view special, or
proprietary, file types that
standard web browsers are not
able to display
– Flash/Shockwave, QuickTime,
Real Audio

8. Network math and IP address
Binary presentation of data
• Computers operate with electronic switches that are
either "on" or "off", corresponding to 1 or 0.
• Computers have to translate in order to use decimal
numbering.

9. Number Systems
• Knowing what base someone refers to
– Decimal uses 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
– Binary uses 2 digits: 0 and 1.
• Base conventions
– 101 in base 2 is spoken as one zero one.
• Working with exponents
– 103 = 10 X 10 X 10 = 1000
– 24 = 2 x 2 x 2 x 2 = 16
• Binary numbers
– Use principle of place value just as decimal numbers do
ASCII
• The American Standard Code for Information Interchange (ASCII) is the
most commonly used code for representing alpha-numeric data in a
computer.
1000011
1001001
1010000
1010100
?

10. Bits and Bytes
• Bits are binary digits. They are either 0s or 1s. In a computer, they are
represented by On/Off switches or the presence or absence of electrical
charges, light pulses, or radio waves.
Base 10 Numbers
Example

11. Base 2 (Binary) Numbers
Converting Decimal to Binary
27 26 25 24 23 22 21 20
128 64 32 16 8 4 2 1
1 1 0 0 1 1 0 1

12. Hexadecimal
• The base 16, or hexadecimal (hex), number system is used
frequently when working with computers, because it can be used to
represent binary numbers in a more readable form.
Converting Binary to Hexadecimal
• Remember that hexadecimal is sometimes abbreviated 0x so hex 5D might
be written as "0x5D".

13. Four-Octet Dotted-decimal Representation of 32-
Bit Binary Numbers
• Currently, Internet Protocol (IP) addresses assigned to
computers on the Internet are 32-bit binary numbers
• The 32-bit binary addresses used on the Internet are
referred to as Internet Protocol (IP) addresses.
IP Addresses and Network Masks
• The IP address of a computer usually consists of a
network, and a host part that represents a particular
computer on a particular network.
• Subnetwork mask a second 32-bit number to identify
how many of the IP address bits are used to identify the
network of the computer.

14. SubnetMask
• A subnet mask will always be all 1s until the network
address is identified and then be all 0s from there to the
right most bit of the mask.
SubnetMask Example
• Converting the IP address 10.34.23.134 to binary
would result in:
00001010.00100010.00010111.10000110
• Performing a Boolean AND of the IP address
10.34.23.134 and the subnet mask 255.240.0.0
produces the network address of this host:
00001010.00100010.00010111.10000110 10.34.23.134 (IP address)
11111111.11110000.00000000.00000000 255.240.0.0 (subnetmask)
00001010.00100000.00000000.00000000 10.32.0.0 (subnetwork address)

15. Address Example
• IP address 10.34.23.134
• Subnetmask 255.0.0.0
• IP address:
00001010.00100010.00010111.10000110 = 10.34.23.134
• Network address:
00001010.00000000.00000000.00000000 = 10.0.0.0
• Broadcast address:
00001010.11111111. 11111111. 11111111=10.255.255.255
View computer address
• ipconfig : brief IP configuration
• ipconfig /all : detail IP configuration
• ipconfig /renew : renew IP address with DHCP
• Practise IP and subnetmask

16. Summary
• The physical connection that has to take place for a
computer to connect to the Internet
• Network interface cards and/or modems
• Web browser selection and configuration
• The Base 2 number system
• Binary number conversion to decimal
• Representasion of IP addresses and network masks