1. Chapter Ten Networking with UNIX

2. Brief History of UNIX System V (1960’s) Versions of UNIX that come from Bell Labs Versions of UNIX that come from Bell Labs Antitrust law prohibited sale Antitrust law prohibited sale BSD (Berkeley Software Division) Versions of UNIX from researchers at the University of California at Berkeley Versions of UNIX from researchers at the University of California at Berkeley Added TCP/IP Added TCP/IP Caldera International and Tarantella jointly own the rights to the UNIX source code The Open Group owns the UNIX trademark

3. Common UNIX Features The ability to support multiple, simultaneously logged in users Hierarchical file systems that incorporate demountable volumes Consistent interfaces for input of data to and output of data from hardware devices, files, and running programs The ability to start processes in the background

4. Common UNIX Features Hundreds of subsystems, including dozens of programming languages Program source code portability Windows interfaces that the user can configure, the most popular of which is the X Window system

5. Current State of the Market Unix market is huge and highly segmented Some real-time implementations of the UNIX system exist In a real-time implementation, the operating system must respond to input immediately In a real-time implementation, the operating system must respond to input immediately NASA – space shuttle & international space station NASA – space shuttle & international space station Two major UNIX market segments Proprietary Proprietary Open source Open source

6. Proprietary UNIX An implementation of UNIX for which the source code is either unavailable or available only by purchasing a licensed copy from Caldera International and Tarantella Sun’s proprietary version of UNIX is called Solaris (for SPARC-based workstations) Sun’s proprietary version of UNIX is called Solaris (for SPARC-based workstations) IBM’s proprietary version of UNIX is called AIX IBM’s proprietary version of UNIX is called AIX HP’s proprietary version of UNIX is called HP- UX HP’s proprietary version of UNIX is called HP- UX

7. Choosing a Proprietary UNIX System Advantages Accountability and support Accountability and support Optimization of hardware and software Optimization of hardware and software Predictability and compatibility Predictability and compatibilityDrawback Customer has no access to the system’s source code and thus cannot create a custom solution Customer has no access to the system’s source code and thus cannot create a custom solution

8. Open Source UNIX Open source software Software developed and packaged by a few individuals and made available to anyone without licensing fees Software developed and packaged by a few individuals and made available to anyone without licensing fees Also called freely distributed software Also called freely distributed software UNIX-like systems in this category include GNU, FreeBSD, and Linux Different implementations of UNIX-like systems are known as flavors Linux – RedHat, Caldera, & Mandrake Linux – RedHat, Caldera, & Mandrake

9. Open Source UNIX Freely distributable versions of UNIX include a copyright called the General Public License (requires the source code to be made available to anyone receiving the system) Freely distributable versions of UNIX include a copyright called the General Public License (requires the source code to be made available to anyone receiving the system) 1991 - Linus Torvalds (then a 2 nd year Finnish computer science student) developed Linux 1991 - Linus Torvalds (then a 2 nd year Finnish computer science student) developed Linux

10. Choosing UNIX UNIX supports TCP/IP, IPX/SPX and AppleTalk protocols UNIX supports Ethernet, Token Ring, FDDI and wireless LANs

11. Choosing UNIX Samba Open source software package Open source software package Complete Windows 2000-style file and print sharing facility Complete Windows 2000-style file and print sharing facility UNIX was originally developed as a time- sharing system Computing system to which each user must attach directly to share the resources of that computer (dumb terminal) Computing system to which each user must attach directly to share the resources of that computer (dumb terminal) Some proprietary UNIX systems have received Orange Book certification U.S. DOD certification U.S. DOD certification

12. UNIX Server Hardware Base system unit must include: Motherboard with CPU, memory, and I/O control Motherboard with CPU, memory, and I/O control Network interface card (NIC) Network interface card (NIC) Floppy disk drive Floppy disk drive CD-ROM drive CD-ROM drive One or more fixed disks One or more fixed disks

13. Decisions in Choosing Hardware Table 10-1: Typical hardware requirements for a Linux server

14. A Closer Look at Linux Linux multiprocessing Supports symmetric multiprocessing (SMP) Supports symmetric multiprocessing (SMP) Linux memory model From its inception, Linux was created to use both physical and virtual memory efficiently From its inception, Linux was created to use both physical and virtual memory efficiently

15. Linux Kernel Kernel As in NetWare, is the core of the system As in NetWare, is the core of the system Also similar to NetWare, it is possible to add or remove functionality by loading and unloading Linux kernel modules Also similar to NetWare, it is possible to add or remove functionality by loading and unloading Linux kernel modules Similar to NetWare NLMs

16. Linux File and Directory Structure Hierarchical file system Organization of files and directories on a disk partition in which directories may contain files and directories Organization of files and directories on a disk partition in which directories may contain files and directories FIGURE 10-1 Linux file system hierarchy

17. Linux File Services Linux includes support for multiple types of file systems, including: Local file systems Local file systems Remote file systems – map to Windows or NetWare Servers Remote file systems – map to Windows or NetWare Servers Its native file system, called ext2 (second extended) Its native file system, called ext2 (second extended) Can access FAT & NTFS (read-only) file systems Can access FAT & NTFS (read-only) file systems Sun Microsystem’s Network File System (NFS) Sun Microsystem’s Network File System (NFS)

18. Linux Internet Services and Linux Processes Linux Internet Services First browsers and servers were developed on UNIX First browsers and servers were developed on UNIX Apache Apache Open source software application that is the leading Internet Web server Linux Processes Another UNIX innovation is the notion of separate, numbered processes Another UNIX innovation is the notion of separate, numbered processes

19. Linux Command Sampler Command interpreter Program that accepts your typing and runs the command Program that accepts your typing and runs the command Also known as a shell Also known as a shell Keeps track of the command history, much like the doskey command in DOS and Windows 2000 Keeps track of the command history, much like the doskey command in DOS and Windows 2000

20. Linux Command Sampler Globbing Form of filename substitution Form of filename substitution Similar to using wildcards in Windows/DOS Similar to using wildcards in Windows/DOSPipe Serves as the connection between two commands Serves as the connection between two commandsPipeline Two or more commands separated by a pipe Two or more commands separated by a pipe

21. Linux Command Sampler TABLE 10-2a: Commonly used Linux commands (p. 493)

22. Linux Command Sampler TABLE 10-2b: Commonly used Linux commands (cont.)

23. Linux Command Sampler Linux systems keep quite a bit of information about each file, including: Filename Filename File size (in bytes) File size (in bytes) Date and time a file’s i-node (file information node) was created Date and time a file’s i-node (file information node) was created Date and time that the file was last accessed Date and time that the file was last accessed Date and time that the file contents were last modified Date and time that the file contents were last modified

24. Linux Command Sampler Information Linux system keeps about each file (cont.): Number of “aliases” or links to the file Number of “aliases” or links to the file Numeric identifier of the user who owns the file Numeric identifier of the user who owns the file Numeric identifier of the group to which the file belongs Numeric identifier of the group to which the file belongs Access rights for the owner, the group, and all others Access rights for the owner, the group, and all others

25. Linux Command Sampler To learn about the i-node information, use the ls command Figure 10-2: Example of output from ls

26. Linux Preinstallation Questions Linux very peacefully coexists with other operating systems on your primary hard drive Read more about multiboot systems at the Linux installation HOWTO site: http://www.linuxhq.com/ldp/howto/Installation- HOWTO/index.html http://www.linuxhq.com/ldp/howto/Installation- HOWTO/index.html http://www.linuxhq.com/ldp/howto/Installation- HOWTO/index.html http://www.linuxhq.com/ldp/howto/Installation- HOWTO/index.html

27. Internetworking with Other Network Operating Systems Samba – Windows file & printer sharing IPX/SPXAppleTalk X3270 – mainframe access WINE – Win32 programming subsystem VMWare – emulate Intel-based computer Dozens and dozens of command-line utilities that enable access to contents of files generated on other systems