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Certificate in E Certificate in E-Governance and Security Information System (CEGCS-04) Vernance and Cyber Certificate in e -Governance and Cyber Security Information System (CEGCS-04) Title Information System Adviso rs Mr. R. Thyagarajan, Head, Admn. & Finance and Acting Director, CEMCA Dr. Manas Ranjan Panigrahi, Program Officer(Education) , CEMCA Prof. Durgesh Pant, Director -SCS&IT, UOU Editor Er. Gopesh Pande, Network Engineer, Wipro Infotech, Mumbai Authors Block I> Unit I, Unit II, Unit III & Unit IV Er. Charanjeet Singh Chawla, Wing Commander, Indian Air Force, Ministry of Defence Block II> Unit I, Unit II, Unit III & Unit IV Er. Ashok Katariya, Group Captain, Indian Air Force, Ministry of Defence Block III> Unit I, Unit II, Unit III & Unit IV Er. Ashok Katariya, Group Captain, Indian Air Force, Ministry of Defence ISBN : 978 -93 -84813 -93 -2 Acknowledgement The University acknow ledges with thanks the expertixe and financial support provided by Commonwealth Educational Media Centre for Asia(CEMCA), New Delhi, for the preparation of this study material. Uttarakhand Open University, 2016 © Uttarak hand Open University, 2016. Information System is made available under a Creative Commons Attribution Share-Alike 4.0 Licence (international): http://creativecommons.org/licenses/by -sa/4.0/ It is attributed to the sources marked in the References, Article Sources and Contributors section. Published by: Uttarakhand Open University, Haldwani Expert Panel S. No. Name 1 Dr. Jeetendra Pande, School of Computer Science & IT, Uttarakhand Open University, Haldwani 2 Prof. Ashok Panjwani, Professor, MDI, Gurgoan 3 Group Captain Ashok Katariya, Ministry of Defense, New Delhi 4 Mr. Ashutosh Bahuguna, Scientist- CERT-In, Department Of Electronics & Information Technology, Government Of India 5 Mr. Sani Abhilash, Scientist- CERT-In, Department Of Electronics & Information Technology, Government Of India 6 Wing Commander C.S. Chawla, Ministry of Defense, new Delhi 7 Mr. Mukesh Kumar Verma, IT Consultant, Chandigarh 8 Mr. Pritam Dutt Gautam, IT Consultant, New Delhi CONTENTS 1.1 LEARNING OBJECTIVES....................................................................................................... 1 1.2 INTRODUCTION TO OSI MODEL ............................................................................................. 1 1.3 SENDING DATA VIA OSI MODEL ............................................................................................ 2 1.4 DIFFERENT TYPES OF PROTOCOLS ....................................................................................... 3 1.4.1 TCP/IP ...................................................................................................................................... 3 1.4.2 IPX/SPX ................................................................................................................................... 3 1.4.3 DECnet ..................................................................................................................................... 3 1.4.4 AppleTalk ................................................................................................................................. 3 1.4.5 NetBIOS ................................................................................................................................... 3 1.4.6 NetBEUI ................................................................................................................................... 3 1.4.7 Server Message Block (SMB) ................................................................................................ 5 1.5 TCP/IP ARCHITECTURE ............................................................................................................. 5 1.5.1 Layered Protocols ..................................................................................................................... 5 1.5.2 IP Routing ................................................................................................................................ 6 1.6 ADDRESSING ............................................................................................................................... 7 1.6.1 The IP Address ......................................................................................................................... 8 1.6.2 Subnets ..................................................................................................................................... 9 1.6.3 Types of Subnetting ............................................................................................................... 10 1.6.3.1 Static Subnetting .............................................................................................................. 10 1.6.3.2 Variable Length Subnetting ............................................................................................. 10 1.6.3.3 Mixing Static and Variable Length Subnetting ............................................................... 11 1.6.3.4 A Static Subnetting Example ........................................................................................... 11 1.7 PRIVATE INTERNETS ............................................................................................................... 11 1.8 CLASSLESS INTER-DOMAIN ROUTING (CIDR) .................................................................. 12 1.9 DOMAIN NAME SYSTEM......................................................................................................... 12 1.10 THE HIERARCHICAL NAMESPACE ..................................................................................... 13 1.11 FULLY QUALIFIED DOMAIN NAMES (FQDNs) ................................................................. 13 1.12 COUNTRY DOMAINS.............................................................................................................. 14 1.13 MAPPING DOMAIN NAMES TO IP ADDRESS .................................................................... 14 1.14 INTERNET PROTOCOL (IP) .................................................................................................... 14 1.14.1 IP Datagram.......................................................................................................................... 15 1.14.2 Direct and Indirect Destinations ........................................................................................... 15 1.14.3 IP Routing Table .................................................................................................................. 16 1.15 INTERNET CONTROL MESSAGE PROTOCOL (ICMP) ...................................................... 16 1.16 TRANSMISSION CONTROL PROTOCOL ............................................................................. 17 1.16.1 Three-Way Handshakes ....................................................................................................... 18 1.17 USER DATAGRAM PROTOCOL ............................................................................................ 18 1.18 PORTS AND SOCKETS ............................................................................................................ 19 1.19 INTERNET PROTOCOLS ......................................................................................................... 22 1.19.1 The Simple Mail Transfer Protocol ...................................................................................... 22 1.19.2 The Mail Transaction ........................................................................................................... 22 1.19.3 Post Office Protocol, version 3 (POP3) ............................................................................... 24 1.19.4 Internet Message Access Protocol (IMAP) .......................................................................... 26 1.20 HOW INTERNET EMAIL WORKS ......................................................................................... 27 1.20.1 Two Flavors of HELO.......................................................................................................... 28 1.20.2 The Sender............................................................................................................................ 28 1.20.3 The recipient ......................................................................................................................... 28 1.20.4 The Message ......................................................................................................................... 28 1.21 FTP .............................................................................................................................................. 29 1.21.1 Basic Commands .................................................................................................................. 29 1.21.2 Initiating a Session ............................................................................................................... 30 1.21.3 Getting What You Want ....................................................................................................... 31 1.22 SSH (SECURE SHELL) ............................................................................................................. 31 1.23 SSL .............................................................................................................................................. 32 1.23.1 How SSL Works................................................................................................................... 32 1.24 SUMMARY ................................................................................................................................ 33 1.25 CHECK YOUR PROGRESS
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