ccna 1 : introduction_to_networking
Post on 26-May-2015
658 Views
Preview:
TRANSCRIPT
CCNA – Semester1
Module 1Introduction to Networking
Objectives
• Network physical connection• Basic computer components• Network math and IP address concept
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
Information flow
Case Study: Boot process
BIOS
OS
SHELL
User Interface
ROM RAM
HDD RAM
RAM IO
Network Interface Cards
• When you select a network card, consider the following three factors:– Type of network– Type of media– Type of system bus
• A network interface card (NIC) is a printed circuit board that provides network communication capabilities to and from a personal computer
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.
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.
TCP/IP Description and Configuration
• Transmission Control Protocol/Internet Protocol (TCP/IP)is a set of protocols or rulesdeveloped 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.
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
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.
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.
1000011100100110100001010100
?
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
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
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".
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.
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)
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
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
top related