Overview

The FHS is maintained by the Free Standards Group, now The Linux Foundation, a non-profit organization consisting of major software and hardware vendors, such as HP, Red Hat, IBM and Dell. However, the vast majority (as of 2009) of the Linux distributions, including those developed by members of the Free Standards Group, do not follow the proposed standard completely. In particular, paths specifically invented by the FHS editors, such as /srv, do not see widespread usage.

Some Linux systems, such as GoboLinux, use a different approach. Also, when it was created, other UNIX and Unix-like operating systems already had their own standards[1][2]. For example, Mac OS X uses longer names such as /Library, /Applications, and /Users in tandem with its traditional UNIX directory hierarchy.

Modern Linux distributions include a /sys directory as a virtual filesystem (Sysfs, comparable to /proc, which is a Procfs), which stores and allows modification of the devices connected to the system, whereas many traditional UNIX and Unix-like operating systems use /sys as a symbolic link to the kernel source tree. Likewise, Plan 9 from Bell Labs includes a /net directory.

History

The process of developing a standard filesystem hierarchy began in August 1993 with an effort to restructure the file and directory structure of Linux. The FSSTND (Filesystem Standard), a filesystem hierarchy standard specific to the Linux operating system, was released on 14 February 1994. Subsequent revisions were released on 9 October 1994 and 28 March 1995.

In early 1996, the goal of developing a more comprehensive version of FSSTND to address not only Linux, but other Unix-like systems was adopted with the help of members of the BSD development community. As a result, a concerted effort was made to focus on issues that were general to Unix-like systems. In recognition of this widening of scope, the name of the standard was changed to Filesystem Hierarchy Standard.

Directory structure

In the FHS all files and directories appear under the root directory “/”, even if they are stored on different physical devices. Note however that some of these directories may or may not be present on a Unix system depending on whether certain subsystems, such as the X Window System, are installed.

The majority of these directories exist in all UNIX operating systems and are generally used in much the same way; however, the descriptions here are those used specifically for the FHS, and are not considered authoritative for platforms other than Linux.

Directory

Description

The file system tree is organized for administrative convenience. Distinct areas within the file system tree are provided for files that are private to one machine, files that can be shared by multiple machines of a common platform, files that can be shared by all machines, and home directories. This organization allows sharable files to be stored on one machine but accessed by many machines using a remote file access mechanism such as NFS. Grouping together similar files makes the file system tree easier to upgrade and manage.

The file system tree consists of a root file system and a collection of mountable file systems. The mount(2) program attaches mountable file systems to the file system tree at mount points (directory entries) in the root file system or other previously mounted file systems. Two file systems, / (the root) and /usr, must be mounted and /var must be accessible to have a functional system. The root file system is mounted automatically by the kernel at boot time; the /usr file system is mounted by the system start-up script, which is run as part of the booting process. /var can be mounted as its own file system or be part of /usr, as it is by default.

Certain locations, noted below, are approved installation locations for bundled Foundation Solaris software. In some cases, the approved locations for bundled software are also approved locations for add-on system software or for applications. The following descriptions make clear where the two locations differ. For example, /etc is the installation location for platform-dependent configuration files that are bundled with Solaris software. The analogous location for applications is /etc/opt/packagename.

In the following descriptions, subsystem is a category of application or system software, such as a window system (dt) or a language (java1.2)

The following descriptions make use of the terms platform, platform-dependent, platform-independent, and platform-specific. Platform refers to a machines Instruction Set Architecture or processor type, such as is returned by uname -i. Platform-dependent refers to a file that is installed on all platforms and whose contents vary depending on the platform. Like a platform-dependent file, a platform-independent file is installed on all platforms. However, the contents of the latter type remains the same on all platforms. An example of a platform-dependent file is compiled, executable program. An example of a platform-independent file is a standard configuration file, such as /etc/hosts. Unlike a platform-dependent or a platform-independent file, the platform-specific file is installed only on a subset of supported platforms. Most platform-specific files are gathered under /platform and /usr/platform.

In the following file or directory descriptions, GNOME stands for GNU Network Object Model Environment. The GNOME Desktop is shipped with the Solaris operating system.

Root File System

The root file system contains files that are unique to each machine. It contains the following directories:

/

Root of the overall file system name space.

/dev

Primary location for special files. Typically, device files are built to match the kernel and hardware configuration of the machine.

/dev/cfg

Symbolic links to physical ap_ids.

/dev/cpu

Provides configuration and capability information about the processor type

/dev/cua

Device files for uucp.

/dev/dsk/dev/dsk

Block disk devices.

/dev/dtrace

Pseudo-devices used by the DTrace framework.

/dev/dtrace/provider

Pseudo-device drivers representing instrumentation providers for the DTrace framework.

/dev/fbs

Frame buffer device files.

/dev/fd

File descriptors.

/dev/md

Logical volume management meta-disk devices.

/dev/printers

USB printer device files.

/dev/pts

Pseudo-terminal devices.

/dev/rdsk

Raw disk devices.

/dev/rmt

Raw tape devices.

/dev/sad

Entry points for the STREAMS Administrative driver.

/dev/sound

Audio device and audio device control files.

/dev/swap

Default swap device.

/dev/term

Terminal devices.

/devices

Physical device files.

/etc

Platform-dependent administrative and configuration files and databases that are not shared among systems. /etc may be viewed as the directory that defines the machine's identity. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /etc/opt/packagename.

/etc/X11

Xorg Xserver (X11) configuration files.

/etc/acct

Accounting system configuration information.

/etc/apache

Apache configuration files.

/etc/apoc

Files for configuring Sun Java Desktop System Configuration Manager remote access.

/etc/bonobo-activation

GNOME XML configuration file for identifying CORBA servers.

/etc/cron.d

Configuration information for cron(1M).

/etc/dat

Contains a list of interface adapters supported by uDAPL service providers.

/etc/default

Defaults information for various programs.

/etc/devices

Contains device-related data.

/etc/dfs

Configuration information for shared file systems.

/etc/dhcp

Dynamic Host Configuration Protocol (DHCP) configuration files.

/etc/dmi

Solstice Enterprise Agents configuration files.

/etc/dt

Desktop configuration files.

/etc/flash

Solaris Flash Archive configuration files.

/etc/fm

Fault manager configuration files. For more information, see fmd(1M).

/etc/fonts

Font configuration information for the GNOME Desktop.

/etc/fs

Binaries organized by file system types for operations required before /usr is mounted.

/etc/ftpd

ftpd configuration files.

/etc/gconf

GNOME Desktop user preference files.

/etc/gimp

GNU Image Manipulation Program (GIMP) configuration files.

/etc/gnome

GNOME Desktop configuration files.

/etc/gnome-vfs-2.0

Files for customizing GNOME 2.0 desktop menus.

/etc/gnopernicus-1.0

Configuration files for GNOME's Gnopernicus, an Assistive Technology (AT) screen reader.

/etc/gss

Generic Security Service (GSS) Application Program Interface configuration files.

/etc/gtk

GNOME configuration files.

/etc/gtk-2.0

GNOME 2.0 Desktop configuration files.

/etc/imq

Sun Java System Message Queue security configuration files.

/etc/inet

Configuration files for Internet services.

/etc/init.d

Shell scripts for transitioning between run levels.

/etc/krb5

Kerberos configuration files.

/etc/lib

Shared libraries needed during booting.

/etc/llc2

Logical link control (llc2) driver configuration files.

/etc/lp

Configuration information for the printer subsystem.

/etc/lu

Solaris Live Upgrade configuration files.

/etc/lvm

Solaris Logical Volume Manager configuration files.

/etc/mail

Mail subsystem configuration.

/etc/nca

Solaris Network Cache and Accelerator (NCA) configuration files.

/etc/net

Configuration information for transport independent network services.

/etc/nfs

NFS server logging configuration file.

/etc/opt

Configuration information for optional packages.

/etc/pam.d

This initially empty directory can be used to configure Kerberos for the GNOME Desktop Managr.

/etc/pango

GNOME 2.0 Desktop locale files.

/etc/patch

Configuration files for patch management.

/etc/ppp

Solaris PPP configuration files.

/etc/rc0.d

Scripts for entering or leaving run level 0. See init(1M).

/etc/rc1.d

Scripts for entering or leaving run level 1. See init(1M).

/etc/rc2.d

Scripts for entering or leaving run level 2. See init(1M).

/etc/rc3.d

Scripts for entering or leaving run level 3. See init(1M).

/etc/rcS.d

Scripts for bringing the system up in single user mode.

/etc/rcm

Directory for reconfiguration manager (RCM) custom scripts.

/etc/rpcsec

This directory might contain an NIS+ authentication configuration file.

/etc/saf

Service Access Facility files.

/etc/sasl

Simple Authentication and Security Layer (SASL) server configuration files.

/etc/security

Basic Security Module (BSM) configuration files.

/etc/sfw

Platform-dependent administrative, configuration files and databases for subsystems from /usr/sfw that are not shared among systems.

/etc/sfw/samba

Samba configuration files.

/etc/skel

Default profile scripts for new user accounts. See useradd(1M).

/etc/sma

Systems Management Agent (SMA) configuration files.

/etc/smartcard

Solaris Smart Card configuration files.

/etc/snmp

Solstice Enterprise Agents configuration files.

/etc/sound

Sound files for the GNOME desktop.

/etc/ssh

Secure Shell configuration files. See ssh(1)

/etc/svc

SMF service repository.

/etc/sysevent

syseventd configuration files.

/etc/subsystem

Platform-dependent subsystem configuration files that are not shared among systems. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /etc/opt/packagename.

/etc/tm

Trademark files; contents displayed at boot time.

/etc/usb

USB configuration information.

/etc/uucp

UUCP configuration information. See uucp(1C).

/etc/xml

Extensible Markup Language (XML) catalog.

/etc/zones

Solaris Zones configuration files

.

/export

Default root of the shared file system tree.

/home

Default root of a subtree for user directories.

/kernel

Subtree of platform-dependent loadable kernel modules required as part of the boot process. It includes the generic part of the core kernel that is platform-independent, /kernel/genunix. See kernel(1M) An approved installation location for bundled Solaris software and for add-on system software.

/kernel/drv

32-bit x86 device drivers.

/kernel/drv/sparcv9

64-bit SPARC device drivers.

/kernel/drv/amd64

64-bit device drivers for 64-bit x86 platforms.

/kernel/dtrace

Kernel modules representing components in the DTrace framework.

/kernel/genunix

Platform-independent kernel.

/kernel/amd64/genunix

64-bit, platform-independent kernel.

/kernel/subsystem/amd64

64-bit x86 platform-dependent modules required for boot. An approved installation location for bundled Solaris software and for add-on system software.

/kernel/subsystem/sparcv9

64-bit SPARC platform-dependent modules required for boot. An approved installation location for bundled Solaris software and for add-on system software.

/lib/svc/manifest

SMF method scripts. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/svc/manifest.

/mnt

Default temporary mount point for file systems. This is an empty directory on which file systems can be temporarily mounted.

/net

Temporary mount point for file systems that are mounted by the automounter.

/opt

Root of a subtree for add-on application packages.

/platform

Subtree of platform-specific objects which need to reside on the root filesystem. It contains a series of directories, one per supported platform. The semantics of the series of directories is equivalent to / (root).

/platform/`uname -i`/kernel

Platform-specific modules required for boot. These modules have semantics equivalent to /kernel. It includes the file unix, the core kernel. See kernel(1M). An approved installation location for bundled Solaris software and for add-on system software.

/platform/`uname -m`/kernel

Hardware class-specific modules required for boot. An approved installation location for bundled Solaris software and for add-on system software.

/platform/`uname -i`/kernel/subsystem/amd64

x86 64-bit, platform-dependent modules required for boot. This is an approved installation location for bundled Solaris software.

/platform/`uname -i`/kernel/subsystem/sparcv9

SPARC 64-bit platform-specific modules required for boot. An approved installation location for bundled Solaris software.

/platform/`uname -i`/kernel/sparcv9/unix

64-bit platform-dependent kernel.

/platform/`uname -i`/kernel/unix

32-bit platform-dependent kernel on i86 and a symlink to sparcv9/unix on SPARC.

/platform/`uname -i`/lib

Platform-specific shared objects required for boot. Semantics are equivalent to /lib. An approved installation location for bundled Solaris software and for add-on system software.

/platform/`uname -i`/sbin

Platform-specific administrative utilities required for boot. Semantics are equivalent to /sbin. An approved installation location for bundled Solaris software and for add-on system software.

/proc

Root of a subtree for the process file system.

/sbin

Essential executables used in the booting process and in manual system recovery. The full complement of utilities is available only after /usr is mounted. /sbin is an approved installation location for bundled Solaris software.

/system

Mount point for the contract (CTFS) and object (OBJFS) file systems.

/tmp

Temporary files; cleared during the boot operation.

/usr

Mount point for the /usr file system. See description of /usr file system, below.

/var

Root of a subtree for varying files. Varying files are files that are unique to a machine but that can grow to an arbitrary (that is, variable) size. An example is a log file. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /var/opt/packagename.

/var/adm

System logging and accounting files.

/var/apache

Scripts, icons, logs, and cache pages for Apache web server.

/var/appserver

Sun Java System Application Server administrative domain files.

/var/audit

Basic Security Module (BSM) audit files.

/var/crash

Default depository for kernel crash dumps.

/var/cron

Log files for cron(1M).

/var/dmi

Solstice Enterprise Agents (SEA) Desktop Management Interface (DMI) run-time components.

/var/dt

dtlogin configuration files.

/var/fm

Fault manager state files. For more information, see fmd(1M).

/var/imq

Message queue broker instance configuration file.

/var/ftp

FTP server directory.

/var/inet

IPv6 router state files.

/var/krb5

Database and log files for Kerberos.

/var/ld

Configuration files for runtime linker.

/var/ldap

LDAP client configuration files.

/var/lib

Login configuration files for GNOME Desktop Manager.

/var/log

System log files.

/var/lp

Line printer subsystem logging information.

/var/mail

Directory where users' mail is kept.

/var/mysql

Dynamic database directory for MySQL Database Management System.

/var/news

Community service messages. This is not the same as USENET-style news.

/var/nfs

NFS server log files.

/var/nis

NIS+ databases.

/var/ntp

Network Time Protocol (NTP) server state directory.

/var/opt

Root of a subtree for varying files associated with optional software packages. An approved installation location for add-on system software and applications.

/var/patchsrv

Patch management log files.

/var/preserve

Backup files for vi(1) and ex(1).

/var/run

Temporary files which are not needed across reboots. Only root may modify the contents of this directory.

/var/sadm

Databases maintained by the software package management utilities.

/var/sadm/system/logs

Status log files produced by software management functions and/or applications. For example, log files produced for product installation. An approved installation location for bundled Solaris software and for add-on system software and applications.

/var/saf

Service access facility logging and accounting files.

/var/samba

Log and lock files for Samba.

/var/sma_snmp

Systems Management Agent (SMA) security and MIB component information.

/var/snmp

SNMP status and configuration information.

/var/spool

Contains directories for files used in printer spooling, mail delivery, cron(1M), at(1), and so forth.

/var/spool/clientmqueue

sendmail(1M) client files.

/var/spool/cron

cron(1M) and at(1) spooling files.

/var/spool/locks

Spooling lock files.

/var/spool/lp

Line printer spool files. See lp(1).

/var/spool/mqueue

Mail queued for delivery.

/var/spool/pkg

Spooled packages.

/var/spool/print

LP print service client-side request staging area.

/var/spool/samba

Samba print queue.

/var/spool/uucp

Queued uucp(1C) jobs.

/var/spool/uucppublic

Files deposited by uucp(1C).

/var/statmon

Network status monitor files.

/var/svc/log

SMF log files.

/var/svc/manifest

SMF service manifests. An approved installation location for bundled, add-on system software and applications.

/var/svc/manifest/site

Site-local SMF service manifests.

/var/tmp

Files that vary in size or presence during normal system operations. This directory is not cleared during the boot operation. An approved installation location for bundled Solaris software and for add-on system software and applications.

/var/uucp

uucp(1C) log and status files.

/var/yp

Databases needed for backwards compatibility with NIS and ypbind(1M); unnecessary after full transition to NIS+.

/usr File System

Because it is desirable to keep the root file system small and not volatile, on disk-based systems larger file systems are often mounted on /home, /opt, /usr, and /var.

The file system mounted on /usr contains platform-dependent and platform-independent sharable files. The subtree rooted at /usr/share contains platform-independent sharable files; the rest of the /usr tree contains platform-dependent files. By mounting a common remote file system, a group of machines with a common platform may share a single /usr file system. A single /usr/share file system can be shared by machines of any platform. A machine acting as a file server can share many different /usr file systems to support several different architectures and operating system releases. Clients usually mount /usr read-only so that they do not accidentally change any shared files.

The /usr file system contains the following subdirectories:

/usr/4lib

a.out libraries for the Binary Compatibility Package.

/usr/5bin

Symbolic link to the /usr/bin directory.

/usr/SUNWale

Configuration files for Asian Lanuguage Environment (ALE).

/usr/X

Symbolic link to the /usr/openwin directory.

/usr/X11

Xorg Xserver (X11) executables and documentation.

/usr/adm

Symbolic link to the /var/adm directory.

/usr/apache

Apache executables, loadable modules, and documentation.

/usr/appserver

Sun Java System Application Server software.

/usr/aset

Directory for Automated Security Enhancement Tools (ASET) programs and files.

/usr/bin

Platform-dependent, user-invoked executables. These are commands users expect to be run as part of their normal $PATH. For executables that are different on a 64-bit system than on a 32-bit system, a wrapper that selects the appropriate executable is placed here. See isaexec(3C). An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin.

/usr/bin/amd64

x86 64-bit, platform-dependent, user-invoked executables. This directory should not be part of a user's $PATH. A wrapper in /usr/bin should invoke the executable in this directory. See isaexec(3C). An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin/amd64.

/usr/bin/sparcv9

SPARC platform-dependent, user-invoked executables. This directory should not be part of a user's $PATH. A wrapper in /usr/bin should invoke the executable in this directory. See isaexec(3C). An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin/sparcv9.

/usr/bin/amd64

x86 platform-dependent, user-invoked executables. This directory should not be part of a user's $PATH. A wrapper in /usr/bin should invoke the executable in this directory. See isaexec(3C). An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin/amd64.

/usr/bin/subsystem

Platform-dependent user-invoked executables that are associated with subsystem. These are commands users expect to be run as part of their normal $PATH. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin.

/usr/subsystem/bin

Platform-dependent user-invoked executables that are associated with subsystem. These are commands users expect to be run as part of their normal $PATH. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin.

/usr/subsystem/bin/amd64

x86 64-bit, platform-dependent, user-invoked executables. This directory should not be part of a user's $PATH. A wrapper in /usr/bin should invoke the executable in this directory. See isaexec(3C). An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin/amd64.

/usr/subsystem/bin/sparcv9

SPARC 64-bit, platform-dependent, user-invoked executables. This directory should not be part of a user's $PATH. A wrapper in /usr/bin should invoke the executable in this directory. See isaexec(3C). An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/bin/sparcv9.

/usr/ccs

C compilation system.

/usr/ccs/bin

C compilation commands and system utilities.

/usr/ccs/lib

Symbolic link to /usr/lib.

/usr/demo

Demo programs and data.

/usr/dict

Symbolic link to the /usr/share/lib/dict directory, which contains the dictionary file used by the UNIX spell program.

/usr/dt

root of a subtree for CDE software.

/usr/dt/bin

Primary location for CDE system utilities.

/usr/dt/include

Header files for CDE software.

/usr/dt/lib

Libraries for CDE software.

/usr/dt/share/man

On-line reference manual pages for CDE software.

/usr/games

An empty directory, a remnant of the SunOS 4.0/4.1 software.

/usr/gnome

GNOME Desktop applications.

/usr/include

Include headers (for C programs).

/usr/j2se

Java 2 SDK executables, loadable modules, and documentation.

/usr/java*

Directories containing Java programs and libraries.

/usr/jdk*

Java Platform virtual machine and core class libraries.

/usr/kernel

Subtree of platform-dependent loadable kernel modules, not needed in the root filesystem. An approved installation location for bundled Solaris software.

/usr/kvm

A mount point, retained for backward compatibility, that formerly contained platform-specific binaries and libraries.

/usr/lib

Platform-dependent libraries, various databases, commands and daemons not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib.

/usr/lib/32

Symbolic link to /usr/lib.

/usr/lib/64

Symbolic link to the most portable 64-bit Solaris interfaces, on both SPARC and x86 platforms.

/usr/lib/acct

Accounting scripts and binaries. See acct(1M).

/usr/lib/adb

adb accounting scripts.

/usr/lib/amd64

Platform-dependent libraries, various databases, commands and daemons not invoked directly by a human user on 64-bit x86. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/amd64.

/usr/lib/autofs

Contains the automountd executable.

/usr/lib/cfgadm

Contains cfgadm hardware-specific driver plugins.

/usr/lib/class

Scheduling-class-specific directories containing executables for priocntl(1) and dispadmin(1M).

/usr/lib/crypto

Contains the kernel-level cryptographic framework daemon (kcfd).

/usr/lib/devfsadm

Contains devfsadm, the daemon version of devfsadm.

/usr/lib/dict

Database files for spell(1).

/usr/lib/dns

Contains DNS resolver libraries.

/usr/lib/dtrace

Contains dtrace D source files.

/usr/lib/flash

Contains Solaris flash archive deployment scripts.

/usr/lib/fm

Contains fmd, the fault manager daemon and the fault manager library.

/usr/lib/font

troff(1) font description files.

/usr/lib/fs

File system type dependent modules; generally not intended to be invoked directly by the user.

/usr/lib/gss

Secure services-related libraries.

/usr/lib/iconv

Conversion tables for iconv(1).

/usr/lib/inet

Contains many network-related daemons and libraries.

/usr/lib/ipf

Contains IPFILTER.LICENCE and ipftest.

/usr/lib/ipqosconf

IPQoS configuration utility.

/usr/lib/krb5

Contains the Kerberos database propagation program and libraries.

/usr/lib/ld

Contains the map files for the ld link editor.

/usr/lib/ldap

Contains LDAP client configuration utilities.

/usr/lib/libp

Profiled libraries.

/usr/lib/llc2

Contains logical link control (llc2) driver configuration files.

/usr/lib/locale

Localization databases.

/usr/lib/lp

Line printer subsystem databases and back-end executables.

/usr/lib/lu

Live Upgrade utilities.

/usr/lib/netsvc

Internet network services.

/usr/lib/nfs

Auxiliary NFS-related programs and daemons.

/usr/lib/nis

Contains NIS+ administrative commands.

/usr/lib/picl

Platform Information and Control Library.

/usr/lib/pool

Contains the automated resource pools partitioning daemon (poold) and associated libraries.

/usr/lib/power

Power management daemon, powerd.

/usr/lib/print

Contains lp conversion scripts and the in.lpd daemon. /usr/lib/rcap

Resource cap enforcement daemon, rcapd.

/usr/lib/rcm

Contains the Reconfiguration and Coordination Manager daemon (rcm_daemon) and RCM scripts.

/usr/lib/refer

Auxiliary programs for refer(1).

/usr/lib/rmmount

Removable media mounter shared objects.

/usr/lib/sa

Scripts and commands for the system activity report package. See sar(1).

/usr/lib/saf

Auxiliary programs and daemons related to the service access facility.

/usr/lib/sasl

Simple Authentication and Security Layer (SASL) plug-in modules.

/usr/lib/secure

Default trusted libraries.

/usr/lib/security

Solaris security plug-in modules.

/usr/lib/smartcard

IFD handler libraries.

/usr/lib/smedia

Removable media device server daemon, rpc.smserverd.

/usr/lib/sparcv9

SPARC 64-bit, platform-dependent libraries, various databases, commands and daemons not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/sparcv9.

/usr/lib/spell

Auxiliary programs and databases for spell(1). This directory is only present when the Binary Compatibility Package is installed.

/usr/lib/ssh

Contains the Secure Shell daemon (sshd) and supporting programs.

/usr/lib/subsystem

Platform-dependent libraries, various databases, commands and daemons that are associated with subsystem and that are not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib.

/usr/lib/subsystem/amd64

x86 64-bit, platform-dependent libraries, various databases, commands and daemons that are associated with subsystem and that are not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/amd64.

/usr/lib/subsystem/sparcv9

SPARC 64-bit, platform-dependent libraries, various databases, commands and daemons that are associated with subsystem and that are not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/sparcv9.

/usr/subsystem/lib

Platform-dependent libraries, various databases, commands and daemons not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib.

/usr/subsystem/lib/amd64

x86 64-bit, platform-dependent libraries, various databases, commands and daemons that are associated with subsystem and that are not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/amd64.

/usr/subsystem/lib/sparcv9

SPARC 64-bit, platform-dependent libraries, various databases, commands and daemons that are associated with subsystem and that are not invoked directly by a human user. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/lib/sparcv9.

/usr/lib/sysevent

Contains the system event notification daemon (syseventd) and the syseventd loadable module (SLM) repository.

/usr/lib/uucp

Auxiliary programs and daemons for uucp(1C).

/usr/lib/vold

Auxiliary vold programs and shared libraries.

/usr/lib/webconsole

Sun Java web console programs and scripts.

/usr/lib/zones

Zone administration daemon (zoneamd).

/usr/local

Not part of the SVR4-based Solaris distribution. The /usr directory is exclusively for software bundled with the Solaris operating system. If needed for storing machine-local add-on software, create the directory /opt/local and make /usr/local a symbolic link to /opt/local. The /opt directory or filesystem is for storing add-on software to the system.

/usr/mail

Symbolic link to the /var/mail directory.

/usr/man

Symbolic link to the /usr/share/man directory.

/usr/net/servers

Entry points for foreign name service requests relayed using the network listener. See listen(1M).

/usr/news

Symbolic link to the /var/news directory.

/usr/oasys

Commands and files related to the Form and Menu Language Interpreter (FMLI) execution environment. See face(1).

/usr/old

Programs that are being phased out.

/usr/openwin

Installation or mount point for the OpenWindows software.

/usr/perl5

Perl 5 programs and documentation

/usr/platform

Subtree of platform-specific objects which does not need to reside on the root filesystem. It contains a series of directories, one per supported platform. The semantics of the series of directories is equivalent to /platform, except for subdirectories which do not provide utility under one or the other (for example, /platform/include is not needed).

/usr/platform/`uname -i`/include

Symbolic link to /../`uname -i`/include. Platform-specific system (sys, vm) header files with semantics equivalent to /usr/include. An approved installation location for bundled Solaris software and for add-on system software.

/usr/platform/`uname -i`/lib

Platform-specific shared objects with semantics equivalent to /usr/lib. An approved installation location for bundled Solaris software and for add-on system software.

/usr/platform/`uname -i`/lib/subsystem/amd64

x86 64-bit, platform-specific daemon and shared objects. An approved installation location for bundled Solaris software and for add-on system software.

/usr/platform/`uname -i`/sbin

Platform-specific system administration utilities with semantics equivalent to /usr/sbin. An approved installation location for bundled Solaris software and for add-on system software.

/usr/preserve

Symbolic link to the /var/preserve directory.

/usr/proc

Directory for the proc tools.

/usr/pub

Symbolic link to /share/lib/pub, which contains files for online man page and character processing.

/usr/sadm

System administration files and directories.

/usr/sadm/bin

Binaries for the Form and Menu Language Interpreter (FMLI) scripts. See fmli(1).

/usr/sadm/install

Executables and scripts for package management.

/usr/sbin

Platform-dependent executables for system administration, expected to be run only by system administrators. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/sbin.

/usr/sbin/install.d

Custom Jumpstart scripts and executables.

/usr/sbin/sparc7 and sparc9

32-bit and 64-bit versions of commands.

/usr/sbin/amd64

64-bit x86versions of commands.

/usr/sbin/subsystem

Platform-dependent executables for system administration, expected to be run only by system administrators, and associated with subsystem. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/sbin.

/usr/subsystem/sbin

Platform-dependent executables for system administration, expected to be run only by system administrators, and associated with subsystem. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/sbin.

/usr/sfw

GNU and open source executables, libraries, and documentation.

/usr/share

Platform-independent sharable files. An approved installation location for bundled Solaris software.

/usr/share/aclocal

Open source m4 files.

/usr/share/applications

Open source desktop applications files.

/usr/share/audio

Sample audio files.

/usr/share/glib-2.0

Makefile for glib.

/usr/share/gnome

GNOME Desktop application registry files.

/usr/share/gtk-2.0

GNOME 2.0 Desktop demo files.

/usr/share/gtk-doc

GNOME 2.0 Desktop help files.

/usr/share/icons

Sun Java Desktop icons.

/usr/share/idl

Open source Interface Definition Language (IDL) files.

/usr/share/intltool

XML translation tools.

/usr/share/ipfilter

Open source IP Filter sample files.

/usr/share/javadoc

Help files for Message Queue broker and Smart Card applications.

/usr/share/lib

Platform-independent sharable databases. An approved installation location for bundled Solaris software.

/usr/share/lib/dict

Contains word list for spell(1).

/usr/share/lib/keytables

Keyboard layout description tables.

/usr/share/lib/mailx

Help files for mailx(1).

/usr/share/lib/nterm

nroff(1) terminal tables.

/usr/share/lib/pub

Character set data files.

/usr/share/lib/tabset

Tab setting escape sequences.

/usr/share/lib/terminfo

Terminal description files for terminfo(4).

/usr/share/lib/tmac

Macro packages and related files for text processing tools, for example, nroff(1) and troff(1).

/usr/share/lib/zoneinfo

Time zone information.

/usr/share/man

Platform-independent sharable manual pages. An approved installation location for bundled Solaris software. The analogous location for add-on system software or for applications is /opt/packagename/man.

/usr/share/omf

GNOME Scrollkeeper database files.

/usr/share/pixmaps

Sun Java graphics.

/usr/share/scrollkeeper

GNOME Scrollkeeper templates and xslt files.

/usr/share/sgml

Open source SGML files.

/usr/share/sounds

Sound files.

/usr/share/src

Source code for kernel, utilities, and libraries.

/usr/share/themes

GNOME 2.0 Desktop themes.

/usr/share/webconsole

Sun Web Console status files.

/usr/share/xml

GNOME Scrollkeeper DTD files.

/usr/snadm

Files related to system and network administration.

/usr/spool

Symbolic link to the /var/spool directory.

/usr/src

Symbolic link to the /usr/share/src directory.

/usr/tmp

Symbolic link to the /var/tmp directory.

/usr/ucb

Berkeley compatibility package binaries.

/usr/ucbinclude

Berkeley compatibility package headers.

/usr/ucblib

Berkeley compatibility package libraries.

/usr/vmsys

Commands and files related to the Framed Access Command Environment (FACE) programs. See face(1).

/usr/xpg4

Directory for POSIX-compliant utilities.

/usr/xpg6

Directory for newer versions of POSIX-compliant utilities.

Linux.

NAME

hier — file system hierarchy

DESCRIPTION

The HP-UX file system is a hierarchical tree organized for administrative convenience. Within the file-system tree structure, distinct areas are provided for files that are private to one machine, files that can be shared by machines, and home directories.

There are two types of files that are shared: those that can be shared by multiple machines of a common architecture, and those that can be shared by all machines. This organization allows sharable files to be stored on one machine (the server), but accessed by many machines (clients).

The following diagram illustrates the file system layout. Note that there are many directories that are not in this diagram, but are discussed below.

The following listing discusses a representative HP-UX directory hierarchy. Some HP-UX applications may add additional directories, which are not shown.

/

Root directory.

/dev

Special files (block and character device files); see mknod(1M).

/etc

Host-specific configuration and administration databases.

/etc/opt

Directory for application-specific configuration files. (Configuration information for optional packages.)

/etc/rc.config.d

Startup configuration files.

/export

Default root of exported file systems. Server only.

/home

Default root for user directories.

/lost+found

Storage directory for connecting detached files; for use by fsck(1M).

/mnt

Mounting point for local file systems.

/net

Mounting point for remote file systems.

/opt

Root of subtree for optional application packages.

/sbin

Essential system commands. Essential commands are defined as executables that are needed to boot the system and mount the file systems. A full complement of utilities is available only after /usr is mounted.

/sbin/init.d

Startup and shutdown scripts.

/sbin/rc0.d

Link files to scripts in /sbin/init.d for entering or leaving run level 0.

/sbin/rc1.d

Link files to scripts in /sbin/init.d for entering or leaving run level 1.

/sbin/rc2.d

Link files to scripts in /sbin/init.d for entering or leaving run level 2.

/sbin/rc3.d

Link files to scripts in /sbin/init.d for entering or leaving run level 3.

/stand

Standalone binaries and kernel configuration files.

/tmp

System-generated temporary files; generally cleared during the boot operation.

/usr

Mount point for sharable user and system administration commands, libraries and documentation.

/usr/bin

Primary location for common utilities and user commands.

/usr/ccs

C compilation system. Tools and libraries used to generate C programs.

/usr/ccs/bin

Development binaries; includes cc, make, strings, etc.

/usr/ccs/lib

Development libraries.

/usr/ccs/lbin

Development backends.

/usr/conf

Kernel configuration files.

/usr/contrib

Directory for user-contributed (unsupported, internal) commands, files, etc. Files in this directory come from outside the local site or organization (for example, from users groups or HP service engineers).

/usr/contrib/bin

User-contributed commands.

/usr/contrib/include

User-contributed include files.

/usr/contrib/lib

User-contributed libraries.

/usr/contrib/man

User-contributed man pages.

/usr/include

Included header files, for C and other programs. Some subdirectories are listed below.

/usr/include/machine

Machine-specific C include files.

/usr/include/nfs

C include files for Network File System (NFS).

/usr/include/sys

Kernel related C-language header files.

/usr/lbin

Directory for backend executables to other commands. A backend executable is an executable that is generally not invoked directly by the user.

/usr/lib

Program libraries, object code and architecture-dependent databases.

/usr/lib/nls

Directory for Native Language Support.

/usr/local

Directory for site-local commands, files, etc. Files under this directory come from inside the local site or organization. See /usr/contrib for non-local unsupported commands and files.

/usr/local/bin

Site-local commands.

/usr/local/lib

Site-local libraries.

/usr/local/man

Site-local man pages.

/usr/newconfig

Default operating system configuration data files. This directory is a directory hierarchy mirroring /. New versions of customizable configuration files and databases are shipped here so as not to overwrite current versions. Files in this directory are copied to regular locations for newly installed systems. System administrators may wish to keep them for later reference.

/usr/old

Files and programs that are being phased out or are obsolete.

/usr/sbin

System administration commands.

/usr/share

Architecture-independent sharable files.

/usr/share/dict

Dictionaries for spell and ispell.

/usr/share/lib

Miscellaneous sharable libraries.

/usr/share/man

Online documentation.

/var

Root of subtree for “varying” files. These are files that are created at runtime and can grow to an arbitrary size. Some examples include log, temporary, transient, and spool files.

/var/adm

System administrative files, such as log files and accounting files. Some of the subdirectories are listed below.

/var/adm/crash

For saving kernel crash dumps.

/var/adm/cron

Directory for cron(1M) queuing.

/var/adm/sw

Default location for software distribution depot.

/var/adm/syslog

Log files generated by syslog. See syslog(3C) and syslogd(1M).

/var/mail

Incoming mail.

/var/news

Local-system news articles for news(1).

/var/opt

Root of subtree for varying files associated with optional software packages.

/var/preserve

Place where ex(1) and vi(1) save lost edit sessions until recovered.

/var/run

Files created when daemons are running. For example, the process ID (PID) file for syslogd, syslog.pid, is put here.

/var/spool

Miscellaneous directories for printer spooling, mail delivery, cron(1M), etc.

/var/spool/cron

cron(1M) and at(1) spooling files.

/var/spool/lp

Printer spool files.

/var/spool/mqueue

Outgoing mail and log files containing messages from the mail system.

/var/spool/uucp

UUCP spool directory.

/var/tmp

Application-generated temporary files. This directory generally is not cleared between system reboots.

/var/uucp

UUCP administration files.

2. Discuss the function of switch?

Ans

Also see repeater, hub, bridge, gateway, and router.

In a telecommunications network, a switch is a device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination. In the traditional circuit-switched telephone network, one or more switches are used to set up a dedicated though temporary connection or circuit for an exchange between two or more parties. On an Ethernet local area network (LAN), a switch determines from the physical device (Media Access Control or MAC) address in each incoming message frame which output port to forward it to and out of. In a wide area packet-switched network such as the Internet, a switch determines from the IP address in each packet which output port to use for the next part of its trip to the intended destination.

In the Open Systems Interconnection (OSI) communications model, a switch performs the layer 2 or Data-Link layer function. That is, it simply looks at each packet or data unit and determines from a physical address (the “MAC address”) which device a data unit is intended for and switches it out toward that device. However, in wide area networks such as the Internet, the destination address requires a look-up in a routing table by a device known as a router. Some newer switches also perform routing functions (layer 3 or the Network layer functions in OSI) and are sometimes called IP switches.

On larger networks, the trip from one switch point to another in the network is called a hop. The time a switch takes to figure out where to forward a data unit is called its latency. The price paid for having the flexibility that switches provide in a network is this latency. Switches are found at the backbone and gateway levels of a network where one network connects with another and at the subnetwork level where data is being forwarded close to its destination or origin. The former are often known as core switches and the latter as desktop switches.

In the simplest networks, a switch is not required for messages that are sent and received within the network. For example, a local area network may be organized in a Token Ring or bus arrangement in which each possible destination inspects each message and reads any message with its address.

Circuit-Switching version Packet-Switching

A network's paths can be used exclusively for a certain duration by two or more parties and then switched for use to another set of parties. This type of “switching” is known as circuit-switching and is really a dedicated and continuously connected path for its duration. Today, an ordinary voice phone call generally uses circuit-switching.

Most data today is sent, using digital signals, over networks that use packet-switching. Using packet-switching, all network users can share the same paths at the same time and the particular route a data unit travels can be varied as conditions change. In packet-switching, a message is divided into packets, which are units of a certain number of bytes. The network addresses of the sender and of the destination are added to the packet. Each network point looks at the packet to see where to send it next. Packets in the same message may travel different routes and may not arrive in the same order that they were sent. At the destination, the packets in a message are collected and reassembled into the original message.

          Getting started with switches

To learn more about switches, here are additional resources

Advanced routing and switching considerations: Routing and switching, the core functions of any network, are becoming more intelligent, with even low-end products now including features once only available to enterprise data centers. Learn the routing and switching considerations that every solution provider should know before offering their services.

Application switch testing: An easy RFP guide: Application switches do a lot more load balancing these days. So network professionals doing application switch testing must consider everything from DPI to basic transport, according to a new Tolly Group RFP guide.

Testing LAN switch interoperability: A series of best practices: Ensuring LAN switch interoperability is crucial when extending existing LANs or building new ones. The Tolly Group compiled a list of functions that must be tested to ensure true interoperability.

          Learn more about Telecom Routing and Switching

Advanced BGP network design for stability and security: Working with Border Gateway Protocol (BGP) in an IP network can challenge even the best network engineers. Yet mastering it will yield a more stable and secure network.

BGP essentials: The protocol that makes the Internet work: Border Gateway Protocol (BGP) is the routing protocol that literally makes the Internet work, yet its complexity makes it essential to know how to troubleshoot problems quickly.

Route maps and routing policy: Route maps and how to configure them for routing policies is explained. This chapter also discusses redistribution, quality of service, and route tagging.

IGP route redistribution, route summarization and default routing: Route redistribution, route summarization and default routing are techniques used to distribute traffic using Interior Gateway Protocols (IGPs).

Which routing protocol? Selecting for optimal routing: One of the toughest questions facing network engineers is which routing protocol to use. This chapter shows you how to evaluate if OSPF, IS-IS or EIGRP is better for your network.

Define Switch

keywords=network, hardware, gear, ethernet, wire, cable, modem, transceiver, hub, router, switch, 10-base T, phone

A switch acts like a network hub. Unlike a plain hub, a switch examines the destination of data packet and only sends it to the physical port needed for proper delivery. Switches can be effective used to reduce cross traffic on growing networks.

Definition: A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model.

Network switches appear nearly identical to network hubs, but a switch generally contains more intelligence (and a slightly higher price tag) than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of each packet, and forwarding them appropriately. By delivering messages only to the connected device intended, a network switch conserves network bandwidth and offers generally better performance than a hub.

As with hubs, Ethernet implementations of network switches are the most common. Mainstream Ethernet network switches support either 10/100 Mbps Fast Ethernet or Gigabit Ethernet (10/100/1000) standards.

Different models of network switches support differing numbers of connected devices. Most consumer-grade network switches provide either four or eight connections for Ethernet devices. Switches can be connected to each other, a so-called daisy chaining method to add progressively larger number of devices to a LAN.

| Definition | In networking, a switch is a small device that joins multiple computers together at a low-level network protocol layer. Technically, network switches operate at Layer Two (Data Link Layer) of the OSI model.

A network switch is a computer networking device that connects network segments.

The term commonly refers to a Network bridge that processes and routes data at the Data link layer (layer 2) of the OSI model. Switches that additionally process data at the Network layer (layer 3 and above) are often referred to as Layer 3 switches or Multilayer switches.

The term network switch does not generally encompass unintelligent or passive network devices such as hubs and repeaters.

The first Ethernet switch was introduced by Kalpana in 1990. [1]

Function

The network switch, packet switch (or just switch) plays an integral part in most Ethernet local area networks or LANs. Mid-to-large sized LANs contain a number of linked managed switches. Small office, home office (SOHO) applications typically use a single switch, or an all-purpose converged device such as gateway access to small office/home office broadband services such as DSL router or cable Wi-Fi router. In most of these cases, the end user device contains a router and components that interface to the particular physical broadband technology, as in the Linksys 8-port and 48-port devices. User devices may also include a telephone interface to VoIP.

In the context of a standard 10/100 Ethernet switch, a switch operates at the data-link layer of the OSI model to create a different collision domain per switch port. If you have 4 computers A/B/C/D on 4 switch ports, then A and B can transfer data between them as well as C and D at the same time, and they will never interfere with each others' conversations. In the case of a “hub” then they would all have to share the bandwidth, run in Half duplex and there would be collisions and retransmissions. Using a switch is called micro-segmentation. It allows you to have dedicated bandwidth on point to point connections with every computer and to therefore run in Full duplex with no collisions.

Role of switches in networks

Network switch is a marketing term rather than a technical one.[citation needed] Switches may operate at one or more OSI layers, including physical, data link, network, or transport (i.e., end-to-end). A device that operates simultaneously at more than one of these layers is called a multilayer switch, although use of the term is diminishing.[citation needed]

In switches intended for commercial use, built-in or modular interfaces make it possible to connect different types of networks, including Ethernet, Fibre Channel, ATM, ITU-T G.hn and 802.11. This connectivity can be at any of the layers mentioned. While Layer 2 functionality is adequate for speed-shifting within one technology, interconnecting technologies such as Ethernet and token ring are easier at Layer 3.

Interconnection of different Layer 3 networks is done by routers. If there are any features that characterize “Layer-3 switches” as opposed to general-purpose routers, it tends to be that they are optimized, in larger switches, for high-density Ethernet connectivity.

In some service provider and other environments where there is a need for a great deal of analysis of network performance and security, switches may be connected between WAN routers as places for analytic modules. Some vendors provide firewall,[2][3] network intrusion detection,[4] and performance analysis modules that can plug into switch ports. Some of these functions may be on combined modules.[5]

In other cases, the switch is used to create a mirror image of data that can go to an external device. Since most switch port mirroring provides only one mirrored stream, network hubs can be useful for fanning out data to several read-only analyzers, such as intrusion detection systems and packet sniffers.

3. In this days why we use the Internet and what are the main services of internet.

Why should my school use computers?

There are three reasons:

          1. They can bring a whole world of information to the students.

  • Here's one example of Educational Tools on the Web.
  • Also, computer skills themselves are becoming essential for the modern workplace. Visit Vice-President Gore's paper and Find “workplace.”

          2. That information can involve students more in learning, making them active learners (in the Piaget tradition) and involved in outreach projects with the real world.

  • To read more, click here and Find “Benefits for Students” and “Community Outreach.”
  • Note that that information can be also organized in ways to encourage logical thought. one example, or click here and Find “tu tor” for another, or here for a third.

          3. They can also help teachers and administrators cope with the rising pace of their professions today.

  • Click here and Find “Professional Development” and “Administrative Uses” for more about this.

How does this fit into other education reforms?

Perfectly.

  • Read about Education Reform and Computers.
  • Compare to John Dewey's classic “Democracy In Education.”
  • Read Vice-President Gore's paper again, as a whole.
  • Read how the Global Schoolhouse Project is bringing these to life. You might Find “quotes” or “goals.”

Are there more examples of these?

Examples of computers used for information:

  • View the Educational Tools list again (on-line museums and other institutions).
  • Look at “among the most complete” on-line museum lists around.
  • Look at some special educationally-appropriate on-line exhibits (includes the Mercury Project, DNA To Dinosaurs, and many more).
  • See a mailing list of NASA projects for kids.
  • Find out about books available on-line.
  • Read about SERC's teaching science and foreign studies.
  • Read about the Computer as Learning Partner science program.

Examples of computers getting students involved:

  • Plugged In, a program that helps teens work with the community.
  • EPGY, a special math program for gifted students.
  • A paper on building K-12 Learning Communities using the World-Wide Web.

Examples of professional resources for teachers:

  • Lloyd Internetworking's List of K-12 Net Curriculums and other net sources.
  • A list of online professional groups and files.
  • The AskERIC HomePage
  • San Diego's Supercomputer Teacher Enhancement Program for high school teachers.
  • Notes on computers and English-as-second-language students.
  • A page on community computing in general, useful as a pattern or partner for classroom computing.

What place does traditional teaching have with computers?

  • Click here and Find “throw away” for a discussion of this.
  • Click here for how the PELICAN project dealt with this question.
  • Here's another example.

How can we really get our school in on this?

It breaks down into four steps: planning (and persuading) for it, connecting to the net, learning how to use it, and creating materials that make use of it.

  • Here's a thorough FYI about connecting schools to the Internet, including Section 4: the two best ways to convince administrators to start an Internet project.
  • NASA's Internet Initiative page, source of the 4-Step approach.
  • Find “Barriers and” in Tracy LaQuey Parker's paper.
  • Here's Web66's simple “ingrediants list” for schools and the Internet.
  • Click here and Find “high expectations” for a discussion of why Creating Materials can make or break a plan.
  • Extra help about funding:
  • Look at the US Department of Education Technology Initiatives plan.
  • Look here for how the PELICAN project was funded.

How many K-12 schools are already on the Internet?

Look at EdWeb's discussion of this (or here for more details), or try Web66's listing of schools on the Web.

What is there to help us use the Internet?

  • Here's the tutorial for the World-Wide Web in general again, and for the browsers for Mosaic, Netscape, and LYNX.
  • Here's the Wisconsin Dept. of Public Education's starter's and K-12 collection of frequently-used Web sites.
  • Visit Web66's page of Web Information.
  • Here's a set of definitions and helps from the University of Michigan.
  • A larger set of general net-help papers.

How does the future look for all this?

  • Find “The Future” in one University of Michigan paper for one view.
  • Or look at the Consortium for School Networking's page for more details.

Are there any more helpful collections on the Web?

Certainly. Here's our Grab Bag of web sites:

  • Organized complexes of sites:
  • Columbia University's vast LiveText collection on the subject, for issues and other information.
  • Information from PBS: EdWeb's Table of Contents.
  • Using Technology In Education by Jack Treuhaft.
  • Overall lists:
  • Netscape's Education Page, divided into different subjects.
  • Yahoo's K-12 listing; large and general.
  • Another large list partly based on Yahoo's, from Spider's Parlor.
  • Sources from The Whole Internet Catalog: Education.
  • A small but handy collection of K-12 sites.
  • Interesting projects and exhibits:
  • Instructional Technology Hot Links.
  • The WWW VirtualLibrary for Education.
  • NASA “Additional Resources”.
  • Large, last-ditch efforts to dig through:
  • The so-called “Ultimate HomePage”
  • Find the “K-12 education” section in this long miscellaneous list.
  • Find “Education” on CMC's list of important credits.
  • The longest list of all: John December's huge collection of general Internet sources

As someone who earns their living entirely online, I
considered myself the last person I ever thought would ask
the question, “Do we really need the Internet?”

However, the extended power outage of almost 4 days, ongoing
loss of Internet access, combined with many other events
surrounding the recent Hurricane Isabel caused me to
reassess my priorities.

When “high-tech” business gets into a head-on collision with
a natural or man-made disaster, we all need to ask, “Do we
really need the Internet?”

Well, when you're in line for 3 hours to get gas so you can
siphon the tank to run your father-in-law's generator in
order to save $1,000 worth of food in three freezers - you
don't need the Internet, you need the expectation that
you'll find gas.

When you're driving around for 2 hours trying to find ice so
you can have a cold drink and make your family more
comfortable on a 90+ degree day - you don't need the
Internet, you need patience and a sense of humor.

When a good friend of yours falls 30 feet off a ladder while
helping his neighbors cut a tree off their house, fractures
his back and neck, punctures a lung and must be airlifted to
the hospital in critical condition - you don't need the
Internet, you need faith he'll be okay!

When the hurricane's destruction threatens to ruin the
surprise 50th wedding anniversary party you've been planning
for over a year for your parents - you don't need the
Internet! You improvise and set up a human communication
network that spreads the word to dozens of people who still
show up and throw a party that creates memories that will
last a lifetime!

When you can't turn on your computer to get work done, you
can still grab a good old-fashioned pen and legal pad and
get more work done in the peace and quiet without phones,
fax or email to distract you than you could ever get done
when things get back to “normal.”

It struck me last night as I struggled to get my high-speed
Internet connection going again that I was much more
stressed over getting a stupid piece of hardware to function
than I was over driving 50+ miles to find gas just two days
before!

In fact, looking back, I was more proud of the fact that on
Saturday I found what was probably the last cold six pack of
beer in all of Southeastern Virginia than I was about my
last successful online product launch!

And after spending many days and nights in the dark, I
realized that the Internet represents the ultimate
convenience, but it's also the ultimate business risk
because so much can happen to shut the Internet down or
prevent you from accessing it.

If recent events taught me anything, they taught me these three truths about life:

  1. Life is fragile and valuable - don't take it for granted.
  2. Nothing is more important than the safety and well-being
    of family and friends. Sometimes it takes a calamity to
    remind us.
  3. Anyone who depends on the Internet for their entire
    livelihood should seek to diversify how they make their
    money - just in case the Internet disappears one day when
    you least expect it!

Types of Internet Services

  • World Wide Web
  • Telnet
  • Electronic Mail
  • FTP - File Transfer Protocol
  • Chat
  • Newsgroups
  • Gopher/WAIS/Archie/Veronica

Gopher/WAIS/Archie/Veronica

  • Gopher - a server that helps you find information on the Internet using menus
  • WAIS - Wide Area Information Servers - searches for documents on the Internet
  • Archie - servers that contain a list of files that can be downloaded using FTP
  • Veronica - a program to search Gopherspace, the world of Gopher menus

Part- B

4. Discuss Run Level in detail with example.

Simply put, a ‘runlevel' determines which programs are executed at system startup. Most of your exposure to run levels will deal with system startup. You will become intimately familiar with the exceptions the first time you have to troubleshoot a failed system.

Linux run levels are numbered 0 through 6. Run levels stop at six for practical and historical reasons, but it is entirely possible to have more if desired.

When run levels are discussed they are referred to as ‘moving into', or ‘going into' a certain run level. The inference is that you came from somewhere. With the exception of booting up, a system always transitions from one runlevel to another in response to certain conditions.

Special Run Levels

Run level 0 is the system halt condition. Nearly all modern X86 computers will power off automatically when run level 0 is reached. Older X86 computers, and various different architectures will remain powered on and display a message referring to the halt condition.

Run Level 1 is known as ‘single user' mode. A more apt description would be ‘rescue', or ‘trouble-shooting' mode. In run level 1, no daemons (services) are started. Hopefully single user mode will allow you to fix whatever made the transition to rescue mode necessary.

(You can boot into single user mode typically by using your boot loader, lilo or grub, to add the word ‘single' to the end of the kernel command line).

Run levels 2 through 5 are full multi-user mode and are the same in a default UserLinux (Debian) system. It is a common practise in other Linux distributions to use run level 3 for a text console login and run level 5 for a graphical login.

Run level 6 is used to signal system reboot. This is just like run level 0 except a reboot is issued at the end of the sequence instead of a power off.

In the interests of completeness, there is also a runlevel ‘S' that the system uses on it's way to another runlevel. Read the man page for the init command (“man init”) for more information, but you can safely skip this for all practical purposes.

Where Does a Run Level Live?

Like everything else in a Linux system, run levels are defined by files in the filesystem. All the run level files are found in the /etc directory according to the following table:

(S)tart files, (K)ill files

Let's look at run level 2 since this is where we'll spend most of our time.

At first glance the files in this directory look kind of intimidating. They should be. The files in the rcX.d directories are formatted for the computer to read, not the user.

Each file is a symbolic link to a script residing in the /etc/init.d directory and controls the starting, or stopping of a program, or daemon (service).

This is important enough to say again, each file is a symbolic link to a script and controls the starting, or stopping of a program, or daemon.

(If you wish to add your own startup script you can do so via the update-rc.d script)

In slightly modified man page format, here is how the files are named:

[K | S] + nn + [string]

Working backwards, here is how the name parses out. The [string] is a human readable mnemonic for the executable file that is actually symbolically linked to. The ‘nn' is a two digit number from 01-99; lower number programs are executed first. By this method, services that have a dependancy can be certain their precursor has ran. The K and S signify simply Kill, or Start.

When a system moves into a new runlevel, all the files that begin with S will be executed. When a system moves into a new runlevel all the files that begin with K will be executed. Yes, all the files will execute, but with one distinct difference: ‘S' files invoke their program with the ‘start' parameter, the ‘K' files invoke their program with the ‘stop' parameter. The UserLinux (Debian) system optimizes the runlevel change by not starting a daemon that is already running.

The simple elegance of this system is made possible by the alphabet. All the scripts will execute in alphabetical order. ‘K' comes before ‘S', so programs are stopped before they are started. Forgetting this fact can lead to a lot of chin scratching while manipulating your rcX.d files.

After the first letter comes the integer, again determining execution order. Finally, the mnemonic portion is followed alphabetically to determine execution order.

All of these files have the same precedence as far as the system is concerned. They will be executed in the order listed, i.e. alphabetically.

All of the scripts that run during system start-up actually reside in the /etc/init.d/ directory, as suggested by the listing. The reasons for this are many, but basically boil down to common sense issues like: saving space, single point for editing, and everyone knowing where to find things.

Transitioning Between Run levels

When you leave a runlevel, nothing happens. All the action takes place when you enter the new run level.

Look intensely at the two listings while allowing your eyes to unfocus. An image of a gnu will eventually appear. Ok, no it won't, but you believed for just a second, didn't you?

Look at the first listing, rc2.d. Notice the contradiction between the first program and the last program. K01xdm instructs the system to Kill xdm upon entering run level 2; S99xdm tells the system to start xdm. Who wins? Both programs are executed, but the last program to run will prevail. S99xdm, as it appears last in the alphabetical sequence, will leave xdm in a running state. The change to runlevel 2 was wasted typing.

Now, let's look closely at the rc3.d listing. The first thing that will be executed is the stopping of gdm, which is the default graphical display manager for UserLinux (Debian). Note the S99gdm file (symlink) has been removed. The purpose of the change is to move to a runlevel where everything else is still running, except the pretty window manager. This situation is called ‘console mode'. As mentioned previously, many Linux distributions use run level 3 for console mode.

That's great, but how do I change run levels?

Before we change run levels it might help to find out which run level is current. Use the ‘runlevel' command to tell you two things: The last run level, and the current run level. Here is the command and the output shown together due to the sparsity of the output:

ulsoho:/home/user1# runlevel

N 2

The ‘N' stands for none, meaning there has been no run level change since powering up.

The init system controls run levels, but then again, the init system pretty much controls everything. The init system will be looked at in detail in a future article.

The primary command used to change run levels is ‘telinit'. Get it? “Tell Init” to do something; like this:

telinit 3

telinit takes one argument on the command line. As always, see the man page for full details. Normally the argument will be one of: 0,1,2,3,4,5,6, or the letter ‘S'. As you may have guessed, the numbers correspond to the run level you wish to move to. Using the ‘S', for single-user, is the same as the number 1, but don't do it; the ‘S' runlevel is intended for use by the UserLinux (Debian)system.

A note of caution is warranted here. You can easily use the telinit command to reboot (run level 6), or shutdown (run level 0) the system, but it is not recommended. Certain programs need special processing for an orderly shutdown. Bypassing the expected shutdown sequence can have dire effects on your data. Older _Unix_ systems are especially sensitive to shutdown/bootup operations

The preferred method for a serious runlevel change is ‘shutdown'. There are easier mnemonics, but in a running system they all point to the ‘shutdown' command. You can use the ‘halt', or ‘poweroff' command to stop a system and the ‘reboot' command to restart your system. In each case they call the ‘shutdown' command with different parameters.

(We've covered shutting down your Debian machine previously)

In a single system (non-networked, or no locally shared resources) environment, the shutdown choice is pretty much yours. However, in a multi-user production system the rule of thumb is learn the shutdown command. The two most basic uses of the ‘shutdown' command are for halting, or rebooting. The important parameter to know for shutdown is WHEN is the action going to occur. Here is the command synopsis from the shutdown man page:

/sbin/shutdown [-t sec] [-arkhncfFHP] time [warning-message]

The vast majority of your shutdowns will follow one of these two forms:

shutdown -h now

or to reboot instead of halt:

shutdown -r now

Intuitively, the arguments mean ‘halt' and ‘reboot', respectively.

In a multi-user system like a file server, the most important parameter is ‘time'. The time can be an actual clock time in the form of HH:MM, or a Julian style shutdown X minutes from now, denoted by the +X syntax. Note that the ‘+' is needed. The keyword ‘now' is synonymous with ‘+0'. Here are two examples using the time parameter:

shutdown -h 16:30

shutdown -r +10

Another important point to remember: once the shutdown command is issued, a notice is sent to all the users of the system and no further logins are allowed. For example, if you need to bring the system down at midnight, don't issue the shutdown command at noon and leave to take a nap. No new users will be able to login for the next 12 hours.

A good admin never takes a system down without warning the user community, but the shutdown notice is only sent after the command is executed! Fortunately, there are two ways around the downtime notification dilemma. The first is the ‘motd', Message Of The Day. The motd is a useful feature that is often overlooked. Using the motd is easy and you are urged to read the simple man page for details. The second method of notification is the -k option. Using -k will send the downtime notice to all the users, but will not actually start the shutdown sequence. There is an important limitation to the shutdown notification: the downtime message is only sent 15 minutes (or less) prior to the actual shutdown.

The warning-message parameter may be useful for...high maintenance users. I find that the default message is authoritative and simple enough to accomplish the task.

Troubleshooting in Run Levels

Here is a tip contributed by Nicholas Petreley. Sometimes you may not want all the programs in a run level to execute. In this situation an easy way to disable a program is to rename it with the initial S, or K in lowercase. The system will ignore all programs that do not begin with a capital S, or K.

Runlevel Definition

A runlevel is a preset operating state on a Unix-like operating system.

A system can be booted into (i.e., started up into) any of several runlevels, each of which is represented by a single digit integer. Each runlevel designates a different system configuration and allows access to a different combination of processes (i.e., instances of executing programs).

The are differences in the runlevels according to the operating system. Seven runlevels are supported in the standard Linux kernel (i.e., core of the operating system). They are:

0 - System halt; no activity, the system can be safely powered down.

1 - Single user; rarely used.

2 - Multiple users, no NFS (network filesystem); also used rarely.

3 - Multiple users, command line (i.e., all-text mode) interface; the standard runlevel for most Linux-based server hardware.

4 - User-definable

5 - Multiple users, GUI (graphical user interface); the standard runlevel for most Linux-based desktop systems.

6 - Reboot; used when restarting the system.

By default Linux boots either to runlevel 3 or to runlevel 5. The former permits the system to run all services except for a GUI. The latter allows all services including a GUI.

In addition to the standard runlevels, users can modify the preset runlevels or even create new ones if desired. Runlevels 2 and 4 are usually used for user defined runlevels.

The program responsible for altering the runlevel is init, and it can be called using the telinit command. For example, changing from runlevel 3 to runlevel 5, which allows the GUI to be started, can be accomplished by the root (i.e., administrative) user by issuing the following command:

telinit 5

Booting into a different runlevel can help solve certain problems. For example, if a change made in the X Window System configuration on a machine that has been set up to boot into a GUI has rendered the system unusable, it is possible to temporarily boot into a console (i.e., all-text mode) runlevel (i.e., runlevels 3 or 1) in order to repair the error and then reboot into the GUI. The X Window System is a widely used system for managing GUIs on single computers and on networks of computers.

Likewise, if a machine will not boot due to a damaged configuration file or will not allow logging in because of a corrupted /etc/passwd file (which stores user names and other data about users) or because of a forgotten password, the problem can solved by first booting into single-user mode (i.e. runlevel 1).

The runlevel command can be used to find both the current runlevel and the previous runlevel by merely typing the following and pressing the Enter key:

/sbin/runlevel

The runlevel executable file (i.e., the ready-to-run form of the program) is typically located in the /sbin directory, which contains mostly administrative tools and which by default is not in the user's PATH (i.e., the list of directories in which the system searches for programs). Thus, it is usually necessary to type the full path of the command as shown above rather than just the name of the command itself.

The default runlevel for a system is specified in the /etc/inittab file, which will contain an entry such as id:3:initdefault: if the system starts in runlevel 3, or id:5:initdefault: if it starts in runlevel 5. This file can be easily (and safely) read with a command such as cat, i.e.,

cat /etc/inittab

As an alternative to telinit, the runlevel into which the system boots can be changed by modifying /etc/inittab manually with a text editor. However, it is generally easier and safer (i.e., less chance of accidental damage to the file) to use telinit. It is always wise to make a backup copy of /etc/inittab or any other configuration file before attempting to modify it manually.

5. Write down the steps to connect to the internet through Linux.

Linux configure modem to connect to the Internet using a PPP dialup account

Q. I want to configure modem to dial out and connect to the Internet. Since I don't have good display card, I am not using the X window system. How do I configure (external) modem to connect to the Internet using a PPP dialup account under Debian Linux?

A. It is true that dialup modems have become almost obsolete due to broadband Internet connections, there are still situations where dialup access can prove useful :)

Under Linux you can dial out using program called wvdial. It is a PPP dialer with built-in intelligence. It dials a modem and starts PPP in order to connect to the Internet. The connection started with wvdial can be dropped by switching back to the terminal from where it was started and pressing ctrl-C.

The default configuration file is: /etc/wvdial.conf.

Installation

Since you are using Debian Linux, use apt-get (assuming that CDROM is your source):

# apt-get install wvdial

Other Linux distribution users can download wvdial from Internet or install from your distribution CD/DVD-ROM disk.

Configuration

First, make sure modem is installed and type the following command to configure the modem:

# wvdialconf /etc/wvdial.conf

Once modem is detected you need to edit /etc/wvdial.conf configuration file to specify the PPP username, password and dial out phone number.

For example:

[Dialer Defaults]

Modem = /dev/ttyS1

Baud = 115200

Init1 = ATZ

Phone = 172226

Username = Your-USERNAME

Password = Your-PASSWORD

Save and close the file.

To connect to internet type command:

# wvdial

To disconnect, switch back to the terminal from where it was started and pressing CTRL+C.

See also:

6. Elaborate network configuration tool. Network configuration tools evolve

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Today's network configuration management products from companies such as AlterPoint, Gold Wire Technology, Intelliden and Tripwire are used mostly to store and track server, router and switch configurations. But industry watchers argue that the technology also can be put to more sophisticated uses to maximize network availability, optimize application performance and secure data centers.

Network configuration management technology automates manual tasks, maximizes efficiency and accuracy by minimizing human error, and “enhances security through tight access controls and configuration audits,” says Glenn O'Donnell, research director at Meta Group.

Increasing Energy Efficiency with x86 Servers: Download now

Available as software-only or packaged as appliances, network configuration management products today capture and store accurate server and device configurations; use automated features to provision and configure new devices; enforce access and change policies; and monitor actions taken on or in relation to devices. Network configuration tools can help maintain consistency across similar devices, ensure critical change data is documented and more quickly restore a device to the known “desired” state - meaning if a failure occurs after a change, network engineers can roll the device back to its known configuration before the change.

Configuration management tools from vendors such as Check Point, Cisco and Nortel offer configuration and change management capabilities for their respective gear, but the predominance of heterogeneous networks creates a demand for multi-vendor products.

Network managers also require software to manage server and application configurations in addition to device information. Companies such as Collation, Relicore and Voyence, among others, have emerged in the past few years to address the need to manage multiple devices from various vendors in a consistent, automated manner.

“It is becoming clear . . . that real improvements in cost control and availability will not happen without configuration management,” Dennis Drogseth, a vice president with Enterprise Management Associates (EMA), wrote in a special report sponsored by configuration management vendor AlterPoint and produced by Network World.

Keeping changes in check

Kevin Schwartz, a network specialist at Burns & McDonnell, an engineering consulting firm in Kansas City, Mo., uses Rendition Networks' TrueControl software to manage changes on switches and routers. The software helped him implement a change management process at his company. In the past, access and authorization to the company's 46 devices (routers and switches) wasn't monitored closely enough.

Tools for Network Configuration

Oracle enables you to manage your network configuration with the following tools: Oracle Net Configuration Assistant, Enterprise Manager, and Oracle Net Manager. Oracle Net Configuration Assistant

The Oracle Universal Installer launches Oracle Net Configuration Assistant after the database is installed. Use Oracle Net Configuration Assistant to configure the listening protocol address and service information for an Oracle database.

During a typical database install, Oracle Net Configuration Assistant automatically configures a listener called LISTENER that has a TCP/IP listening protocol address for the database. If you do a custom install, Oracle Net Configuration Assistant prompts you to configure a listener name and protocol address of your choice.

Use Oracle Net Configuration Assistant for initial network configuration after database installation. Thereafter, you can use the Oracle Enterprise Manager and Oracle Net Manager to configure and administer your networks.

Enterprise Manager

Enterprise Manager enables you to manage your server-side network configuration with two pages: the Listener page and the Net Services Administration page.

The Listener page displays the listener status and enables you to shut it down. You can navigate to this page from the Home page by clicking the Listener link under General. See “Viewing Listener Configuration” in this chapter.

You can navigate to the Net Services page from the Home page by clicking Listener under General. The Listener page appears. Under Related Links, click Net Services Administration.

The Net Services Administration page enables you to do the following:

  • Perform the following administrative tasks for a selected listener:
  • Show current status
  • Change status (start/stop listener)
  • Change tracing settings
  • Change logging settings
  • Configure the following:
  • Listener
  • Local naming (tnsnames.ora files) on the machine running the database
  • Directory naming
  • Search and sort local and directory naming entries
  • Export directory naming entries to tnsnames.ora file

Oracle Net Manager

You can access Oracle Net Manager from the command line or for Windows platforms through the Start menu.

  • For command line (UNIX, Linux, or Windows) run netmgr.
  • On Windows click the Start button and select Programs, Oracle - oracle_home, Configuration and Migration Tools, and then Net Manager

Oracle Net Manager provides the same features as Oracle Enterprise Manager with the addition of configuring profiles. To learn how to use this tool, see “Configuring Oracle Networking on Client Machines”.

Overview

The Network Interfaces Configuration and Network Services Configuration product (bundle name, NetworkConf) is used to configure and manage network interfaces and network services on a HP-UX system. These two plug-ins can be launched from the HP System Management Homepage (HP SMH).

The Network Interfaces Configuration and Network Services Configuration product is the Networking and Communications functional area that was available in the System Administration Manager (SAM). SAM is deprecated in HP-UX 11i v3 and moving forward will be unavailable.

Network Interfaces Configuration

Network Interfaces Configuration tool is used for configuring APA, NIC, RDMA, VLAN, Tunnel, HyperFabric, and X.25 interfaces. Network Interfaces Configuration provides the following features:

  • The NIC tab enables the user to manage network interface cards. It auto detects LAN interfaces if they are installed on the system. When you install LAN drivers, Network Interfaces Configuration automatically detects the interfaces and makes it available for you to configure the interface. You need not install additional patches to configure the interface.
  • The APA tab enables the user to manage link aggregates.
  • The RDMA tab enables the user to reset RDMA interfaces and perform Critical Resource Analysis (CRA) on a selected RDMA interface.
  • The VLAN tab enables the user to manage virtual LANs.
  • The Tunnels tab enables the user to configure and manage tunnel interfaces.
  • The HyperFabric tab enables the user to start and stop HyperFabric on the node, and configure and manage HyperFabric network interface cards.

Network Interfaces Configuration provides a web-based graphical user interface (GUI) and a text user interface (TUI).

Network Services Configuration

Network Services Configuration tool is used for configuring various network services. Network Services Configuration comprises the following components:

  • Bootable Devices
  • Fixed-Address Devices Booting From this Server
  • DHCP Device Groups Booting From this Server
  • Devices for which Boot Requests are Relayed to Remote Servers
  • DHCPv6
  • Configuring Default DHCPv6 Client Settings
  • Configuring DHCPv6 Server
  • Configuring a Host to act as a DHCPv6 Relay Agent
  • Configuring DHCPv6 Relay Interface Mappings
  • Configuring DHCPv6 Address Pools
  • Configuring DHCPv6 Client Duid Groups
  • Configuring DHCPv6 Device Groups
  • DNS
  • DNS Local Name Server
  • DNS Resolver
  • Hosts
  • Local Hosts File
  • NIS Hosts Map
  • Name Service Switch
  • Network Services
  • NIS
  • Route
  • Networked File Systems
  • Automounted Remote File System
  • Local Netgroups
  • NIS Netgroups
  • Share/Unshare File Systems(Export FS)
  • System Access
  • Internet Services
  • Remote Logins
  • Time
  • NTP Broadcasting
  • NTP Network Time Sources
  • System Clock
  • Network News
  • Inbound Newsfeeds
  • Outbound Newsfeeds

In the HP-UX 11i v3 release, Share/Unshare File Systems provides a web-based graphical user interface and a text user interface. All other components provide X-Window based user interface.

Fedora - Network configuration

Network configuration on Fedora is quite similar to the one for other versions of RedHat Linux, besides the standard files, the main configuration is done on /etc/sysconfig/network where is defined the hostname and can be placed the default gateway and in the files of the /etc/sysconfig/network-scripts/ directory.

The TCP/IP network setup is done with the script /etc/init.d/network, with obviously must be started before other network services on a connected machine. The official graphical configuration tool is system-config-network (Menu System Settings - Network), from here is possible to define the IP parameters for all the interfaces found on the system (tab Devices, modifies the /etc/sysconfig/network-scripts/ifcfg-interface and /etc/sysconfig/networking/devices/ifcfg-interface files), the IP of the DNS servers (tab DNS, modifies /etc/resolv.conf), the static host IP assignement (tab Hosts, modifies /etc/hosts).

Fedora supports also user's profiles, with differnet network settings. The Network Configuration tools easily let the user define a profile and its parameters, the relevant system files are placed in the directory /etc/sysconfig/networking/profiles/profilename/. Currently Fedora does not allow the definition of a profile at boot time, when the machine is started the default “Common” profile is used, to switch to a custom one either launch system-config-network graphical tool and select your profile or type system-config-network-cmd -p profilename --activate.

RedHat provides other network configuration tools: netconfig is an old text configuration tool, which is obsolete and may be used to a fast configuration; system-config-network-tui is the text version of the graphical Network Configuration Tool. system-config-network-druid (Menu System tools - Internet configuration wizard) is a guided wizard which helps an easy configuration of Ethernet, modem, ISDN, DSL, wireless configuration.

Firewall configuration

Red Hat stores the firewall configuration in the /etc/sysconfig/iptables file which is formatted in order to be used by the iptables-restore command. Firewalling is managed with the /etc/init.d/iptables script which can be followed by arguments like start to activate firewalling, stop to disable it, panic to shutdown any Internet access, status to view the current iptables rules.

A simple and not extremely flexible configuration tool is system-config-firewall, which is adeguate for a desktop machine but surely not for a router/firewall.