NETWORK+ GUIDE TO NETWORKS, FOURTH EDITION - CHAPTER 9 docx

Network+ Guide to Networks, Fourth Edition Chapter Networking with UNIX-Type of Operating Systems Objectives • Describe the origins and history of the UNIX operating system • Identify similarities and differences between popular implementations of UNIX • Describe the features and capabilities of servers running Solaris, Linux, and Mac OS X Server • Explain and execute essential UNIX commands Network+ Guide to Networks, 4e Objectives (continued) • Install and configure Linux on an Intel-based PC • Manage users, groups, and file access permissions in Solaris, Linux, and Mac OS X Server • Explain how computers running other operating systems can connect to UNIX servers Network+ Guide to Networks, 4e A Brief History of UNIX • UNIX led to development of TCP/IP • Numerous vendors sell different UNIX varieties • Ken Thompson and Dennis Ritchie developed UNIX at Bell Labs (part of AT&T) – System V • UNIX source code was cheaply available from AT&T – Quickly distributed to many organizations Network+ Guide to Networks, 4e A Brief History of UNIX (continued) • Berkeley Software Distribution (BSD): Berkeley versions of UNIX – Added TCP/IP network subsystem to UNIX • AT&T sold rights to UNIX – Now owned by two groups: • The SCO Group owns rights to UNIX source code • The Open Group owns UNIX trademark Network+ Guide to Networks, 4e Varieties of UNIX • All flavors of UNIX share the following features: – – – – Support multiple, simultaneously logged-on users Coordinate multiple, simultaneously running tasks Mount disk partitions on demand Apply permissions for file and directory access and modification – Uniform method of issuing data to or receiving data from hardware devices, files, and running programs – Start programs without interfering running programs Network+ Guide to Networks, 4e Varieties of UNIX (continued) • All flavors of UNIX share the following features (continued): – Hundreds of subsystems, including dozens of programming languages – Source code portability – Window interfaces (e.g., X Windows) • Two main categories: – Proprietary – Open source Network+ Guide to Networks, 4e Proprietary UNIX • Source code either unavailable or available only by purchasing licensed copy from the SCO Group – Mac OS X Server: Apple • Runs on PowerPC-based computers – Solaris: Sun • Runs on SPARC-based workstations and servers, Intel-based Pentium-class workstations and servers – AIX: IBM • Runs on PowerPC-based computers • Does not run on Macs Network+ Guide to Networks, 4e Proprietary UNIX (continued) • Advantages: – Accountability and support – Optimization of hardware and software – Predictability and compatibility • Customer has no access to system’s source code – Cannot customize Network+ Guide to Networks, 4e Open Source UNIX • Open source software available to anyone, without licensing fees • Open source UNIX flavors: – GNU – BSD – Linux • Users can modify code – Add functionality • Can be installed on wide range of systems Network+ Guide to Networks, 4e 10 Installing and Configuring Fedora Core • Installation tasks: – – – – – – – – – Select language Confirm keyboard layout Select Server installation type Select disk drive partitioning options Choose booting options Configure the network interface(s) Configure firewall and security level options Set the time and time zone Enter the root password Network+ Guide to Networks, 4e 32 Administering a UNIX-type of Server • User names and passwords used to connect clients to network • Access rights for groups – Users may be members of multiple groups • groupadd command enables addition of new group • useradd command enables addition of new users • Mac OS X Server uses GUI Workgroup Manager application Network+ Guide to Networks, 4e 33 Establishing Groups and Users on Linux and Solaris • groupadd command creates new group ID and makes group available for use – Assign unique ID number to each group – Does not automatically assign access rights • useradd command adds new user ID – Creates user ID and assigns it to one or more groups – -g option specifies initial group – -G option specifies additional groups Network+ Guide to Networks, 4e 34 Establishing Groups and User on Mac OS X Server • Use Workgroup Manager application • Creating new group does not assign users • Assign unique name and numeric ID to groups Network+ Guide to Networks, 4e 35 Establishing Groups and User on Mac OS X Server (continued) Figure 9-4: User creation in Mac OS X Server’s Workgroup Manager Network+ Guide to Networks, 4e 36 Changing File Access Permissions • Every file and directory is owned by exactly one user and is a member of exactly one group • By default, when a user creates a file or directory, that user is the file or directory’s owner Network+ Guide to Networks, 4e 37 Changing File Access Permissions on Linux and Solaris • Use chgrp command to assign a file or directory to a group • Use chmod command to change file and directory permissions – Uses two sets of abbreviations to specify permission changes for files • First set identifies for whom change will occur [file’s owner (u for “user”), file’s group (g), all others (o)] • Second set identifies access rights [read (r), write (w), and execute (x)] • Separated by plus or minus sign Network+ Guide to Networks, 4e 38 Changing File Access Permissions on Mac OS X Server • Accomplished through the GUI • Must be logged on as system administrator Network+ Guide to Networks, 4e 39 Connecting to UNIX-Type of Servers • UNIX-type of systems and Windows can both communicate via TCP/IP – File systems not necessarily compatible • Samba: one application that bridges file system incompatibility – Provides networking services necessary to make a UNIX-type system a fully featured Windows file- and printer-sharing server – Communicates with Windows servers using SMB file-sharing protocol and CIFS protocol Network+ Guide to Networks, 4e 40 Connecting to UNIX-Type of Servers (continued) • All modern flavors of UNIX, Linux, and Mac OS X Server support data sharing using directory services based on LDAP – Solaris: Sun Java System Directory Server Enterprise Edition – Linux: OpenLDAP – Mac OS X Server: Open Directory • UNIX-type of systems include full complement of Internet tools – e.g., Telnet Network+ Guide to Networks, 4e 41 Connecting to UNIX-Type of Servers (continued) Figure 9-5: Windows Telnet session Network+ Guide to Networks, 4e 42 Summary • UNIX is a stable, flexible, and efficient NOS that relies on TCP/IP and forms the basis of much of the Internet • Many varieties of UNIX-type of systems exist, and each of these belong to one of two categories: proprietary and open source • Characteristics of UNIX-type of systems include the ability to support multiple, simultaneous users; hierarchical files; a uniform method for interacting with files, devices, and programs; hundreds of subsystems and dozens of programming languages; and source code portability Network+ Guide to Networks, 4e 43 Summary (continued) • UNIX-type of systems use virtual memory and also allocate a memory area for each application • The UNIX kernel, the core of the OS, is loaded into memory from disk and runs when you turn on your computer • UNIX-type of systems were among the first to include a hierarchical file system • UNIX-type of systems support multiple file system types • UNIX-type of network file systems include NFS and Samba Network+ Guide to Networks, 4e 44 Summary (continued) • Consult the command’s manual (man) page by typing man command at the shell prompt, and pressing Enter to learn more about a command • ls command is most frequently used command • The useradd and groupadd commands allow you to add new users and groups • The chgrp and chmod commands assign files to groups and change file access permissions Network+ Guide to Networks, 4e 45 Summary (continued) • Installing the Samba application on a UNIX-type of server allows it to exchange information with Windows servers by using Windows file system and file access protocols • All modern flavors of UNIX, Linux, and Mac OS X Server support data sharing using directory services based on LDAP • Any client that runs the TCP/IP protocol can connect to a UNIX-type of host, such as a Linux server, through the Telnet utility Network+ Guide to Networks, 4e 46 ... input to next – Pipeline: two or more commands connected by a pipe Network+ Guide to Networks, 4e 29 A UNIX Command Sampler (continued) Figure 9- 3 : Anatomy of ls –l output Network+ Guide to Networks,. .. (continued) Table 9- 4 : Commonly used UNIX commands Network+ Guide to Networks, 4e 26 A UNIX Command Sampler (continued) Table 9- 4 (continued): Commonly used UNIX commands Network+ Guide to Networks,. .. Network+ Guide to Networks, 4e 12 Solaris Hardware Requirements Table 9- 1 : Minimum hardware requirements for Solaris 10 Network+ Guide to Networks, 4e 13 Linux Hardware Requirements Table 9- 2 : Minimum