1. Welcome to Early Bird Class Networking And IT Security Ravi Chandra Gurung

2. Our Game Plan Computer Networking Day 1: Introduction to Networking Day 2: IP address system DHCP Gateway NAT Router Setup Computer Operating System Day 3: Introduction to Operating System Day 4: Basic Linux Command OS Installation File Sharing Day 5: Web Server Configuration DNS Server Configuration FTP Server Configuration Computer Security Day 6: Introduction to Security Types of attack Process of attack Introduction to hacking tools and techniques Counter Measures against attack

3. Review of Day 2 IP address system (IPv4) DHCP Gateway NAT

4. What is an Operating System ? Introduction to Operating System A modern computer consists of: One or more processors Main memory Disks Printers Various input/output devices. Managing all these varied components requires a layer of software – the Operating System (OS).

5. What is an Operating System ? Introduction to Operating System An Operating System is a system software that acts as an intermediary/interface between a user of a computer and the computer hardware. OS goals: Control/execute user/application programs. Make the computer system convenient to use. Ease the solving of user problems. Use the computer hardware in an efficient manner.

6. Where does the OS fit in? Introduction to Operating System *Kernel - A kernel is the central part of an operating system. It manages the tasks of the computer and the hardware - most notably memory and CPU time.

7. Computer System Components Introduction to Operating System Hardware – provides basic computing resources (CPU, Memory, I/O devices, Communication). Operating System – controls and coordinates use of the hardware among various application programs for various users. System & Application Programs – ways in which the system resources are used to solve computing problems of the users (Word processors, Compilers, Web browsers, Database systems, Video games). Users – (People, Machines, other computers).

8. Dynamic View of System Components Introduction to Operating System

9. SYSTEM view of OS Introduction to Operating System OS is a resource allocator Manages all resources (CPU time, memory space, storage space, I/O and so on) Decides between conflicting requests for efficient and fair resource use OS is a control program Controls execution of programs to prevent errors and improper use of the computer Controls execution of user programs and operation of I/O devices. Kernel The program that executes forever (everything else is an application with respect to the kernel).

10. Motherboard Introduction to Operating System

11. History Introduction to Operating System  It all started with computer hardware in about 1940s. ENIAC 1943

12. History Introduction to Operating System  ENIAC (Electronic Numerical Integrator and Computer), at the U.S. Army's Aberdeen Proving Ground in Maryland.  built in the 1940s,  weighed 30 tons,  was eight feet high, three feet deep, and 100 feet long  contained over 18,000 vacuum tubes that were cooled by 80 air blowers.

13. Today’s Systems Introduction to Operating System Principles of Operating Systems - Lecture 113

14. Today’s Systems Introduction to Operating System

15. Types of Operating Systems Introduction to Operating System Single-user, single task As the name implies, this operating system is designed to manage the computer so that one user can effectively do one thing at a time. The Palm OS for Palm handheld computers is a good example of a modern single-user, single-task operating system. Palm OS is a mobile operating system initially developed by Palm, Inc., for personal digital assistants (PDAs) in 1996. Palm OS was designed for ease of use with a touchscreen-based graphical user interface. It is provided with a suite of basic applications for personal information management.

16. Types of Operating Systems Introduction to Operating System Single-user, multi-tasking This is the type of operating system most people use on their desktop and laptop computers today. Microsoft's Windows and Apple's MacOS platforms are both examples of operating systems that will let a single user have several programs in operation at the same time. For example, it's entirely possible for a Windows user to be writing a note in a word processor while downloading a file from the Internet while printing the text of an e-mail message.

17. Types of Operating Systems Introduction to Operating System Multi-user – operating system It allows many different users to take advantage of the computer's resources simultaneously. The operating system must make sure that the requirements of the various users are balanced, and that each of the programs they are using has sufficient and separate resources so that a problem with one user doesn't affect the entire community of users. Unix, VMS (virtual memory system) and IBM mainframe operating systems, such as MVS (Multiple Virtual Storage), are examples of multi-user operating systems.

18. Types of Operating Systems Introduction to Operating System Network operating System It runs on a server and provides server the capability to manage data, users, groups, security, applications, and other networking functions. The primary purpose of the network operating system is to allow shared file and printer access among multiple computers in a network, typically a local area network (LAN), a private network or to other networks. Examples of network operating systems are Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell NetWare, and BSD (Berkeley Software Distribution). The advantages of network operating systems are following.  Centralized servers are highly stable.  Security is server managed.  Upgrades to new technologies and hardware's can be easily integrated into the system.  Remote access to servers is possible from different locations and types of systems.

19. Types of Operating Systems Introduction to Operating System Real Time operating System Real time system is defines as a data processing system in which the time interval required to process and respond to inputs is so small that it controls the environment. Real-time systems are used when there are rigid time requirements on the operation of a processor or the flow of data and real-time systems can be used as a control device in a dedicated application. Real-time operating system has well-defined, fixed time constraints otherwise system will fail. For example Scientific experiments, medical imaging systems, industrial control systems, weapon systems, robots, and home appliance controllers, Air traffic control system etc.

20. Types of Operating Systems Introduction to Operating System Mobile operating System A mobile operating system (or mobile OS) is an operating system for smartphones, tablets, PDAs, or other mobile devices. Mobile operating systems combine features of a personal computer operating system with other features useful for mobile or handheld use Essential in modern mobile systems; a touchscreen, cellular, Bluetooth, Wi-Fi, GPS mobile navigation, camera, video camera, speech recognition, voice recorder, music player, near field communication and infrared blaster.

21. Mobile operating System Introduction to Operating System Android (operating system) Google Android OS. Android (based on the Linux Kernel) is from Google Inc. Android market share was 53.2% 1.1 - Alpha 1.2 - Beta 1.5 - Cupcake 1.6 - Donut 2.0.x & 2.1 - Eclair 2.2.x - Frozen Yogurt ("Froyo") 2.3.x - Ginger Bread (Minor UI Tweak) 3.x.x - Honeycomb (Major UI revamp) 4.0.x - Ice Cream Sandwich (Minor UI Tweak) 4.1.x, 4.2.x & 4.3.x - Jelly Bean 4.4.4 - KitKat 5.0.1 & 5.1.1 - Lollipop (Major UI revamp) 6.0 Beta 4 - Android M (Marshmallow)

22. Mobile operating System Introduction to Operating System iOS is from Apple Inc. It has the second largest installed base worldwide on smartphones By August 2015, iOS global market share was 41.56%. Current iOS's version list: iPhone OS 1.x iPhone OS 2.x iPhone OS 3.x iOS 4.x iOS 5.x iOS 6.x iOS 7.x (Major UI revamp) iOS 8.x *iOS 9 Beta 5 (Current) *iOS 9.x (September, 2015)

23. Mobile operating System Introduction to Operating System Windows Phone (Soon to be Windows 10 Mobile) is from Microsoft. It is closed source and proprietary. By the end of 2014, Windows Phone global market share was 2.7%. Windows Phone 7 Windows Phone 7.5 Windows Phone 7.8 (Minor UI tweak) Windows Phone 8 (GDR1, GDR2 & GDR3) & (Minor UI tweak) Windows Phone 8.1 (GDR1 & GDR2) & (Minor UI tweak) Windows 10 Mobile developer preview 14219 (Major UI revamp)

24. Mobile operating System Introduction to Operating System BlackBerry 10 (based on the QNX OS) is from BlackBerry. As a smart phone OS, it is closed source and proprietary. Once one of the dominant platforms in the world, its global market share has been reduced to 0.4% by the end of 2014. Current BlackBerry 10's version list: BlackBerry 10.0 BlackBerry 10.1 BlackBerry 10.2 BlackBerry 10.3 (Major UI revamp)

25. Introduction to Operating System

26. Thank you