Transcript Tollbooths & Highways
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
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
Year 1960’s 1970’s 1980’s 1990s 1998 2000s Speed (bits/sec) 300 300 4600 28800 56000 2,000,000 Application Connecting Dumb terminals to Mainframe computer Bulletin boards introduced Transferring files and graphics Widening use of the internet More graphic based web pages and file transfers Introduction 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 127.0.0.1 – 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 B inary dig ITS 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 = 0 -255
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 1.2.5 Decimal to Binary Conversion
Lab 1.2.6 Binary to Decimal Conversion
Lab 1.2.8 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. 192.168.10.143
Has 2 parts
Network portion Host Portion
Has a Subnet Mask
255.0.0.0
255.255.0.0
255.255.255.0
Subnet Masks
Subnet Mask is used to identify the network portion if the address
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 255.0.0.0
produces the network address of this host: 00001010.00100010.00010111.10000110
11111111.00000000.00000000.00000000
00001010.00000000.00000000.00000000 Network Address = 10.0.0.0
Subnet Masks
Performing a Boolean AND of the IP address 10.34.23.134 and the subnet mask 255.255.0.0
produces the network address of this host:
Answer 00001010.00100010.00010111.10000110
11111111.11111111.00000000.00000000
00001010.00100010.00000000.00000000 Network Address = 10.34.0.0