Linux Administration

Linux is a modern, flexible, and mature operating system. Although it started life on the Intel platform, it has since been ported to many other platforms such as Amiga, DEC Alpha, Apple Power PC, Sun workstations, and others. The new Red Hat Linux 6.3 release continues this line of improvement by offering a graphical user interface (GUI) to the installation and configuration process.

Open Source and Free Software

All Linux distributions are based on the same idea: Take the Linux kernel and surround it with freely available software to create a usable operating system. Red Hat Linux 6.3 used Linux kernel 2.6. Red Hat Software continuously evolves their distribution by using the most current, stable kernel as well as the latest available software for each of its distributions.

History

  • Although Linux came into being in 1991, it can trace its lineage back much further.

  • In 1969, a Bell Labs programmer named Ken Thompson invented the Linux operating system.

  • Around the same time, another programmer, Dennis Ritchie, was working on a new computer language called C. By 1974, the two had rewritten Linux in the C language, and ported it to several different machines.

  • It is this combination of Linux and C that Linux owes much of its heritage to. Linux and C are at the heart of Linux and the Open Source movement.

  • Linus Torvalds is the world’s most famous computer programmer. He is the founder and coordinator of Linux, the Linux-like operating system that is beginning to revolutionize the computer industry.

  • At the time, he had been using another Linux-like operating system called Minix, a microkernel-based teaching operating system. Minix had many limitations, however, so Linus set about writing a new operating system that did not suffer the limitations of MS-DOS and Minix.

  • Linux was by no means the first person to come up with the idea of a free Linux-like operating system. Several years earlier The Free Software Foundation, headed by Richard M. Stallman, announced a kernel called The HURD.

  • In 1996 a stable version of The HURD was available. William and Lynne Jolitz in 1991 were also busy porting Berkeley Linux, BSD, to the Intel platform.

GPL and Open source licenses

The terms―Free‖ and ―Open Source‖ software are commonly used to mean the same thing. While the differences are subtle, they are very important.

Free Software

  • Free software is the term typically used to refer to software that has been released under the GNU Public License, or G Today, the Linux kernel is developed the same as it was in the beginning.

  • The term “Free software” is sometimes misunderstood-it has nothing to do with price. It is about freedom. To clear up some of the confusion, the following is the definition of free software.

  • Since “free” refers to freedom, not to price, there is no contradiction between selling copies and free software. In fact, the freedom to sell copies is crucial: collections of free software sold on CD-ROMs are

  • Important for the community, and selling them is an important way to raise funds for Free software development. Therefore, a program that people are not free to include on these collections is not free software

About Linux

You hear people talking about Linux all the time. But you also probably hear about the “Red Hat” Linux distribution, and names like SuSE, Caldera, Debian, Slackware, and others.

Are they all Linux?

  • Recall that Linux is the operating system kernel. That is, kernel is heart of the operating system.

  • However, like all operating systems, to be useful, Linux has to have utilities and programs to do the actual work. This is where distributions come in.

  • All of the Linux distributions run the Linux kernel. But after that, the distributions vary from each other to some degree.

  • For example, the Slackware distribution looks and feels much like Berkeley Linux, whereas the SuSE distribution is much more System V.

  • Red Hat Linux tends to fall somewhere in between but is leaning toward System V more and more with each new release.

Current support for networking services

Linux supports many different networking protocols:

TCP/IP

  • The Internet Protocol was originally developed two decades ago for the United States Department of Defense (DOD), mainly for the purpose of interconnecting different-brand computers.

  • The TCP/IP suite of protocols allowed, through its layered structure, to insulate applications from networking hardware.

  • TCP/IP networking has been present in Linux since its beginnings.

  • It has been implemented from scratch. It is one of the most robust, fast and reliable implementations and is one of the key factors of the success of Linux.

TCP/IP version 6

IPv6, sometimes also referred to as IPng (IP Next Generation) is an upgrade to the IPv4 protocol in order to address many issues. These issues include: shortage of available IP addresses, lack of mechanisms to handle time-sensitive traffic, lack of network layer security, etc.

IPX/SPX

IPX/SPX (Internet Packet Exchange/Sequenced Packet Exchange) is a proprietary protocol stack developed by Novell and based on the Xerox Network Systems (XNS) protocol. IPX/SPX became prominent during the early 1980s as an integral part of Novell, Inc.’s NetWare.

Linux has a very clean IPX/SPX implementation, allowing it to be configured as an:]

  • IPXrouter

  • IPXbridge

  • NCP client and/or NCP Server (for sharing files)

  • NovellPrintClient,NovellPrintServer

  • Enable PPP/IPX, allowing a Linux box to act as a PPP server/client

  • PerformIPXtunnelingthroughIP,allowingtheconnectionoftwoIPXnetworksthroughan

  • IP

AppleTalk Protocol Suite

  • AppleTalk is the name of Apple’s internetworking stack. It allows a peer-to-peer network model which provides basic functionality such as file and printer sharing.

  • Each machine can simultaneously act as a client and a server, and the software and hardware necessary are included with every Apple computer.

  • Linux provides full AppleTalk networking. Net talk is a kernel-level implementation of the AppleTalk Protocol Suite, originally for BSD-derived systems.

  • It includes support for routing AppleTalk, serving Linux and AFS file systems over AFP (AppleShare), serving Linux printers and accessing AppleTalk printers over PAP.

  • WAN Networking: X.25, Frame-relay, etc…

  • Several third parties provide T-1, T-3, X.25 and Frame Relay products for Linux.

  • Generally special hardware is required for these types of connections.

  • Vendors that provide the hardware also provide the drivers with protocol support.

ISDN

The Linux kernel has built-in ISDN capacities. Isdn4linux controls ISDN PC cards and can emulate a modem with the Hayes command set (“AT” commands). The possibilities range from simply using a terminal program to connections via HDLC (using included devices) to full connection to the Internet with PPP to audio applications.

PPP, SLIP, PLIP

The Linux kernel has built-in support for PPP (Point-to-Point-Protocol), SLIP (Serial Line IP) and PLIP (Parallel Line IP). PPP is the most popular way individual users access their ISPs (Internet Service Providers). PLIP allows the cheap connection of two machines. It uses a parallel port and a special cable, achieving speeds of 10kBps to 20kBps.

Amateur Radio

The Linux kernel has built-in support for amateur radio protocols. Especially interesting is the AX.25 support. The AX.25 protocol offers both connected and connectionless modes of operation, and is used either by itself for point-point links, or to carry other protocols such as TCP/IP and NetRom.

ATM

  • ATM support for Linux is currently in pre-alpha stage. There is an experimental release, which supports raw ATM connections (PVCs and SVCs), IP over ATM, LAN emulation etc…

  • Red Hat announces the general availability of Red Hat Linux 6, which offers enhanced performance, reliability, scalability, security and more.

  • Red Hat has announced the general availability of Red Hat Enterprise Linux 6.3, the first update to the platform since the delivery of Red Hat Enterprise Linux 6 in November 2010.

  • Red Hat delivered Red Hat Enterprise Linux 6.3 to key partners at its Red Hat Summit in early May, but now making the operating system generally available.

  • With Red Hat Enterprise Linux 6.3, Red Hat continues to set the standard in flexibility, performance and quality that customers rely on for their open-source enterprise environments, spanning physical, virtual and cloud deployments, the company said.

  • The enhancements in Red Hat Enterprise Linux 6.3 provide customers with improvements in system reliability, scalability and performance, coupled with support for upcoming system hardware.

  • And Red Hat Enterprise Linux 6.3 also delivers patches and security updates, while maintaining application compatibility and original equipment manufacturer and independent software vendor (OEM/ISV) certifications.

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