CCNA 1 : introduction_to_networking
- 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