Introduction to Networking CCNA 1, Module 1 By Steven Beckwith

Aims  By the end of this chapter you should be able to:  Understand the fundamentals of Internet Connectivity  Describe the basic components of a PC’s Hardware and Software  Demonstrate TCP/IP Configuration and testing  Diferentiate between High Speed and Dialup Connectivity  Understand and demonstrate Decimal, Binary and Hexadecimal conversion and Boolean Logic  Show a basic understanding of IP Addresses and Subnet Masks

Internet Fundamentals  The Internet  A network of Interconnected Networks  Computers can exist without the Internet but the Internet cannot exist without computers  The Internet can be thought of as a Tree The trunk and branches are the pathways connecting networks The leaves are the computers

Internet Connectivity  Computers connect to the internet in a number of ways, can you list them?  Dial-up (Modem)  ISDN  DSL  Cable  Network

PC Basics (Components)  Electronic components  Transistor  Integrated Circuit (IC)  Resistor  Capacitor  Connector  Light Emitting Diode (LED)

PC Basics (Components)  PC components  Printed Circuit Board (PCB)  CD-ROM drive  Central Processing Unit (CPU)  Floppy Disk Drive  Hard Disk Drive  Microprocessor  Motherboard  Random Access Memory (RAM)

PC Basics (Components) Contd.  PC components  Read Only Memory (ROM)  Bus  Expansion Slots  System Unit  Power Supply

PC Motherboard Components  Backplane  Memory Chip  Network Interface Card (NIC)  Video Card  Sound Card  Parallel Port  Serial Port  Mouse Port  Keyboard Port  Power Cord  Universal Serial Bus (USB) Port

Desktop Vs Laptop  Desktop  Comes in two styles Desktop Tower  Used in the home and at work  Not suitable for mobile use  Connects directly to network via NIC  Can connect to network via a modem

Desktop Vs Laptop  Laptop  Comes in a variety of styles Laptop Palmtop Compact  Gives flexibility to mobile users  Connects directly to network via NIC  Can connect to network via modem and Cellular Telephone

Selecting a NIC  Points to consider  Type of network Ethernet Token Ring FDDI  Type of Medium Twisted pair Coaxial Fiber Wireless

Selecting a NIC (Contd).  Points to consider  Type of System bus ISA PCI USB PCMCIA

High Speed and Dialup YearSpeed (bits/sec) Application 1960’s300Connecting Dumb terminals to Mainframe computer 1970’s300Bulletin boards introduced 1980’s4600Transferring files and graphics 1990s28800Widening use of the internet More graphic based web pages and file transfers 2000s2,000,000Introduction of broadband for home users

TCP/IP  A set of Protocols to allow computers on different networks to communicate  Used to access the Internet  PC Requires:  An IP Address  Subnet Mask  Default Gateway  This information is obtained from the network administrator

TCP/IP Configuration

TCP/IP Testing Ping  A protocol used to test TCP/IP Connectivity  Stands for Packet Internet Groper  Sends multiple IP packets to destination computer (typically 4 -packets)  Will receive the same number of replies  Information obtained will allow you to ascertain network connectivity

IPConfig  Used to verify current IP configuration  Lab 1.1.6

Ping  Procedures for verifying connectivity Ping – Internel loopback address Ping IP Address of host computer – Verifies own configuration Ping default gateway IP address – verifies router can be accessed Ping remote IP address – verifies connectivity to remote host

Tracert  Traces the route traffic takes from source to destination  Lab 1.1.7

Decimal Notation  All Number systems consist of symbols and rules for using them  We use the Decimal number system  Consists of the symbols 0,1,2,3,4,5,6,7,8,9.

Binary Notation  Computers use Binary notation  Information is stored in memory as a 1 (on) 0r 0 (off)  Has only 2 symbols 0 and 1  Called Binary digITS  Usually represented in groups of 8 BITS  8 BITS = 1 Byte or Octet  1024 bytes = 1 Kilobyte (Kb)  1024 Kb = 1 Megabyte (Mb)  1024 Mb = 1 Gigabyte (Gb)

Binary Notation  Possible combinations of 1s and 0s in 8 bits =

Hexadecimal Notation  Computers represent large numbers as Hexadecimal  Has 16 symbols, numbers 0-9 and A, B,C, D, E, F representing 10 – 15.

Number Conversions  Lab Decimal to Binary Conversion  Lab Binary to Decimal Conversion  Lab Hexadecimal Conversions

Boolean Logic  Boolean logic is based on digital circuitry that accepts one or two incoming voltages.  Based on the input voltages, output voltage is generated.  For the purpose of computers the voltage difference is associated as two states, on or off.  These two states are in turn associated as a 1 or a 0, which are the two digits in the binary numbering system.

Logic Gates  NOT  The NOT operation takes whatever value is presented, 0 or 1, and inverts it.  A one becomes a zero and a zero becomes a one.

Logic Gates  AND  The AND operation takes two input values.  If both are 1, the logic gate generates a 1 output.  Otherwise it outputs a 0.

Logic Gates  OR  The OR operation also takes two input values.  If at least one of the input values is 1, the output value is 1

IP Addressing  An IP Address is a 32 bit address represented in Decimal notation for ease of reading  eg  Has 2 parts  Network portion  Host Portion  Has a Subnet Mask   

Subnet Masks  Subnet Mask is used to identify the network portion if the address  Converting the IP address to binary would result in:  Performing a Boolean AND of the IP address and the subnet mask produces the network address of this host:   Network Address =

Subnet Masks  Performing a Boolean AND of the IP address and the subnet mask produces the network address of this host:  Answer  Network Address =

Good luck in the test!