CCNA

1. Cisco Network Support Certifications 2. Networking Terms 3. INTRODUCTION TO NETWORKING 4. TYPES OF NETWORK 5. The Development of the Internet 6. NETWORK ARCHITECTURE 7. TOPOLOGY 8. BUS TOPOLOGY 9. RING TOPOLOGY 10. STAR TOPOLOGY 11. MESH TOPOLOGY 12. HYBRID TOPOLOGY 13. Speed of Networking device 14. NETWORK DEVICES 15. Exploring Wireless Network 16. REPEATERS 17. HUB 18. SWITCH 19. BRIDGE 20. ROUTERS 21. TRANSMISSION Telecommunication 22. Difference between Full Duplex, Half Duplex and Simplex 23. IP-ADDRESSING and IPV4 24. IPv4 address classes 25. IPV6 [ Internet Protocol Version 6 ] 26. SPEED OF VARIOUS DEVICES 27. Network Security 28. Some basic suggestion and steps to prevent Attacks and Network security 29. OSI model 30. UPPER and LOWER Layer 31. Application Layer (Layer 7) 32. Presentation Layer (Layer 6) 33. Session Layer (Layer 5) 34. Transport Layer (Layer 4) 35. Network Layer (Layer 3) 36. Data Link Layer 2 37. Physical Layer 1 38. TCP/IP The DoD Model 39. ROUTED PROTOCOL 40. Ports and Application 41. Important Application, Protocol and Port Number 42. Router Function 43. Types of Routing Protocols 44. STARTING ROUTER 45. CISCO IOS 46. Logging in to the Router 47. CISCO Router IOS commands List 48. Setting time and date of router 49. Router configuration commands 50. Optimizing Switch and Router 51. Understanding Router Terms 52. ROUTER SECURITY 53. Configuring CISCO SWITCH Security Policy 54. IMPLEMENTING STATIC ROUTING 55. UNDERSTANDING THE NEED FOR NAT 56. WAN Connections 57. Access List [ACL] 58. VLAN [Virtual Local Area Network] 59. SPANNING TREE :- BROADCAST STORM 60. Lab 1 Setting up a Serial Interface 61. Lab 2 : IP Addressing 62. Lab 3 Static Routes 63. Lab 4 Default Routes 64. Lab 5 RIP Routes 65. Lab 6 IGRP Routes 66. Lab 7 EIGRP Routes 67. Lab 8 OSPF Routes 68. Lab 9 CHAP and RIP 69. Lab 10 Standard Access-Lists with RIP 70. Lab 11 Extended Access-Lists with RIP 71. Lab 12 Static NAT 72. Lab 13 Many to One NAT 73. Lab 14 NAT Pool 74. Lab 15 ( 2950 Trunk ) 75. Lab 16 ( 2950 Trunk Dynamic ) 76. Lab 17 (2950 VLANs) 77. Lab 18 ( 2950 Deleting VLANs ) 78. Lab 19 ( 2950 VTP ) 79. Lab 20 ( 2950 VTP w/ client ) 80. Lab 21 ( 2950 Telnet )
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OSI model [ Open Systems Interconnection model ] tutorials

  • The OSI model is the foundation for all communication that takes place between computers and other networking devices. The (ISO) International Organization for Standardization began developing the OSI model in 1974, after DOD (Department of Defense) developed and began using the TCP/IP (Transmission Control Protocol / Internet Protocol). TCP / IP is a suite of protocols that work together to provide communication. After many years of discussion, the OSI model was finally adopted in 1977. Today OSI model is used as the theoretical model for how communication takes place between devices. Though it is theoretical model, it defines the way in which devices interact and understanding the OSI model will help to design, implement and troubleshoot any network.

  • Each layer of the OSI model is independent from every other in its purpose and responsibilities. Each layer must do its own job, as well as provide service to layer above and below it. In this way model create framework. The OSI model provide a structure for software programmers and equipment manufacturers to develop products that will work together. This is known as interoperability.

 

 

Application

(Layer 7)

 

This layer provides a user interface. It supports application for communication over the network

SMTP (Simple Mail Transfer Protocol), HTTP (Hyper Text Transfer Protocol), FTP (File Transfer Protocol) work at this layer.

 

 

 

 

Presentation

(Layer 6)

 

 

It performs data Presentation, Compression and Encryption so that it is recognizable by the receiver. For most common computer native format is ASCII (American Standard Code for Information Interchange) while for IBM mainframe it would be EBCDIC (Extended Binary Coded Decimal Interchange Code)

 

 

 

Session

(Layer 5)

 

It Establishes connections, keeps different applications data separate, then terminates them after all the data has been sent. It send syn (Synchronization) packets to establish connection, while receiver send back ack acknowledgement .

 

 

 

 

 

Transport

(Layer 4)

 

data is converted into SEGMENT

 

Provides reliable transport method, Acknowledgement, error correction and retransmission of data when necessary. It makes sure that sender and receiver communicate at speed they both can handle called flow control i.e. 2 Ghz & 500 Mhz communicate @ 500 mhz.

 

 

Network

(Layer 3)

 

Segment converted into PACKET

 

It adds appropriate network addressing and delivery of packets called Datagrams. It provides logical addressing which router use for path determination.

 

 

Data Link

(Layer 2)

 

PACKET converted into FRAME

 

Combine packets into bytes and bytes into frames. It adds the MAC addresses to frames. It performs error detection not correction.

 

 

Physical

(Layer 1)

 

FRAME converted into BITS

 

Transmit data on the wire. Moves bits between devices. Specify voltage, wire speed and pin-out of cable. This layer is responsible for actual physical connection between devices. It may uses Coaxial, CAT, Fiber Optic cable or wireless for communication

 

 

Advantages of OSI model

  • It divides the network communication process into smaller and simpler components, thus aiding component development, design and troubleshooting.

  • It assists in data transfer between different hosts, i.e. it enables us to transfer data between UNIX to WINDOWS to MAC.

  • It allows multiple vendor development though standardization of network components.

  • It allows various types of network hardware and software to communicate.

 

DATA Encapsulation

  • When a host transmits data across a network to another device the data goes through encapsulation. It is wrapped with protocol information at each layer of the OSI mode. Each layer communicates only with same layer on the receiving device.

  • To communicate and exchange information, each layer attach header in front of data and also at trailer or end. When it reaches to receiving end, each layer then understands header and trailer and passes data to upper layer.

 

 

 

 

 

 

 

 

APPLICATION

 

 

 

 

 

 

 

 

PRESENTATION

 

 

 

 

 

Upper Layer Data

 

 

SESSION

 

 

 

 

Tcp. Header

Upper Layer Data

 

 

TRANSPORT

Segment

 

 

 

 

 

 

 

 

 

 

IP header

Upper Layer Data

 

 

NETWORK

Packet

 

 

 

 

 

 

 

 

 

Logic Link Header

UPPER LAYER DATA

Trailer

 

DATA LINK

Frame

 

 

 

 

 

 

 

 

Mac Add.

UPPER LAYER DATA

Trailer

 

PHYSICAL

Bits

Bits 11000111001111101111101111111

 

 

 

 

  • At a transmitting device data encapsulation method works like this.

 

Segment

 

 

 

 

 

 

 

Source

Port

Destination

Port

Data

 

 

 

 

 

 

 

 

 

 

 

Packet

 

 

 

 

Source

IP

Destination

IP

Protocol

Segment

 

 

 

 

 

 

 

 

 

 

 

Frame

 

Destination

MAC

Address

Source

MAC Add

Ether-

field

Packet

Trailer

 

 

 

 

 

 

 

 

 

 

Bits

 

Bits 11000111001111101111101111111


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