Certification Central - Recently Updated Pages

Certification Central

Dr.Disk — Wed, 26 Nov 2008 20:18:17 CST

Welcome to the Certification Central wiki!

O.K., so I admit it, I'm a Geek! There's no 12 step program for a technology addiction, so, I've had to learn to live with my problem. In fact, I've turned it into my career. About 10 years ago I received my CNA (Certified Novell Administrator) and CNE (Certified Novell Engineer) certifications and have been able to keep those current.

Recently, the position I had been at for nine years was outsourced and I found myself "pounding the pavement" looking for a new job. One thing I discovered is that the job market for technology has become a very specialized place. No longer is a Network Administrator expected just to manage accounts. It's become a world full of CISCO, Linux and Lean Sigma Six!

I've realized, if I want to stay competative I need to catch up and get additional certifications! This wiki is dedicated toward reaching that goal. Before I found myself in this awesome new position, I had started my jouney toward the darkside (i.e., achieving status as a Microsoft Certified Systems Engineer). I still plan on achieving that goal and you will find details about that over the coming months. In the meantime, I plan on achieving my Linux+ certification and then moving on towards my CCNA. While this site is mainly to keep myself organized and on task towards certification nirvana, feel free to use the review pages and notes provided within to assist you in achieving your own goals! Who knows, one day you may become a Super Geek!

Live on Selfcast!

Note to Educators: Wetpaint Wikis that support learning are now advertising free! Find out how to qualify by visiting http://www.wetpaint.com/category/Education--Ad-free

Tips for Building a Wiki:

Rename your home page to something more specific about your classroom
Add images and widgets (like YouTube videos and polls)
Invite other students to help! (Click on "Invite others" in the Page Toolbox)
Use person-to-person messages to stay in touch with your classmates and teacher.

Need more? Add graphics and flourishes that match your wiki design (they're free from Paint Splatters)

Section 5: Users and Groups

Dr.Disk — Tue, 24 Jun 2008 10:35:08 CDT

Target Goals

Create users and groups
Manage users
Manage groups

Default Accounts

root - equivelent to admin on other systems
bin
daemon
ftp
sshd
nfsnobody
apache
squid

"The Root" of the issue
root maintains the system and creates users

SU (substitute user)
use the su command to login as root witout logging off.
suroot to run commands that which reuire a root login.

Linux+ Certification

Dr.Disk — Tue, 27 May 2008 07:42:28 CDT

I'm fairly new to the world of Linux and have been somewhat hesitant to jump on board the technology wagon with the OS. I have found it too be difficult to work with from an administrative standpoint, namely installation issues and driver maintenance. That being said, I see the potential for this open source product. And since my company has been kind enough to put me through a Linux+ boot camp, I plan on attaining the Linux+ certification. So, here you will find my notes from the bootcamp.

I am working with both the SUSE and Ubuntu distributions of Linux for the purposes of these notes. Inside you will find references to both Distros. I will switch back and forth between them in the following pages. You will see one of the following icons in each instance.

When you see this lovely lizard
I am referring to SUSE Linux which is Novell's implementation of Linux

This icon represents Ubuntu which is a more "tweaked" version of Debian Linux

Without further ado, let's jump into the deep end! No floaties required...

Section 1: Installing Linux

Section 2: Getting to Know Linux

Section 3: The Linux Filesystem

Section 4: File Manipulation

Section 5: Users and Groups

Section 4: File Manipulation

Dr.Disk — Mon, 19 May 2008 15:05:16 CDT

Target Goals

Locate files
Create linked files
Create and edit files
Back up and restore files

Locating Files

The Find Command

find [search_locations] [search criteria] [actions] - used to find locate in specified locations based on conditions provided.
Once files are found additional actions may be performed

Multiple search paths may be used can include directory notations.

Because find will search the directory and subdirectories the file or directory must meet all specified criteria before being reported.

Find Options

Condition	Search by	Result
-name	File or Directory name	Pattern can be full name or "" and metacharacters can be used to define sections of name
-type	File, Directory, other	d = directory f = file often combined with name
-user	Ownership	argument = user name
-group	Group Membership	argument = group name

\! = notates "not" and is used to create exception when placed before search criteria

Options once a file is located

Switch	Result
-print	Print to screen
-exec	Execute command
-ok	Execute interactively

Locate Command
locate - used to find data files, programs, directories and objects matching keywords against a database named slocate.db. locate should be updated prior to being run by logging in as root and running updatedb or slocate -u. locate only searches by name use find to search by attribute and whereis to search for commands

Grep
grep allows you to search contents of files.

grep foo test will show all lines that match foo in the file test.
Using ls -l | grep ball will return all files within the current directory containing the word ball.

Linking Files
Linking files in Linux is like making shortcuts in windows.

ln - allows a file name in one directory to point to a file name in another directory

Symbolic vs. Hard Links

Remember a link does not contain data but acts as a pointer.

Symbolic Link - allows a single file or directory to be accessible via multiple file names.

Hard Link - Looks like a real file to all applications.(it is more like a copy). Even if original deleted contents still available via linked file. Links may only be created on the same partition and cannot be created for directories.

Create and Edit Files

Text Editors

Vi
Included in most versions of UNIX and Linux used for program development but can become a letter-quality word processor. Use Vi to create shell scripts.

Open the Vi editor using the vi command. This will open an unnamed file.

Command Mode - used to save, edit, search, replace and other "administrative" tasks

Input mode- type text into vi file. No commands are available

Changing Modes (Input and Append)

Mode	Function
i	Input mode; inserting text to left of cursor
a	Append mode; input text to right of cursor
l	Insert mode; input text at beginning of line
A	Append mode; input text at end of line
ESC	Return to command mode

Replacing Text

Mode	Function
r	Replaces one character
R	Replaces characters until you press ESC
cw or ce	Deletes from cursor to beginning of word and puts you in insert mode, ESC returns to command mode
cb	Deletes from cursor to beginning of word and puts you in insert mode, ESC returns to command mode
c$ or U	Deletes rest of line and puts you in insert mode, ESC returns to command mode

Copying and Deleting

Mode	Function
x	Deletes One Character at a time
yy	Places a copy of current line in buffer
dd	Deletes curent line and places in buffer
p	Inserts copied or deleted line into file below line of cursor
P	Inserts copied or deleted line into file above line of cursor

Undo
Return to command mode using Esc and press U to undo changes. This removes changes one by one each time you press U.

Save and Exit Vi
Saving from command mode :w [filename]

:q - used to quit Vi once file is saved
:q! - forces Vi closed without saving

Vi Edit commands
Type Result
g move left one character
j move down one line
k move up one line
l move right one character
^ Move to beginning of current line
$ Move to last line in file
:[number] Move to line specified by number
w next word
b previous word
e move to end of current word or next word if already at the end of a word
Ctrl+U Move up 1/2 screen
Ctrl+D Move down 1/2 screen
Ctrl+F Move down one full screen
Ctrl+B Move up one full screen

Stream Editor
sed - modifies lines from a specified file by command or script and writes results to display

Linux isn't awkward but awk is!
/[pattern]/ searches for specific pattern or entry in files. Once the first occurance is found N will start the search for the next.
! (NOT), && (AND), and || (OR) will help narrow and widen searches

Output Redirection
ls >list tells shell to output command results to the file list. It will create the file if it doesn't exist

Input Redirection
< informs shell to redifine input as a non-keyboard device, usually a file.

Back Up and Restore Files

Archiving
tar - allows you to archive files. (-c = creating an archive -f = create a file with the name that follows)
The destination is the location and name of the file; the source is the location and name of the file or directory to use to create the archive.

Tape archiving to and from remote media is most common but you can create local backups as well.

-r is used to append or update a tar file. If source is new it gets appended. New versions will overwrite.
-v places you in verbose mode (will also list names of files being archieved or copied)
tar -tvf [tarfilename] - -t lists contents of tar file. -v long listing of contents -f with [filename] specifies the file.

Backing up directories uses the same command as backing up files

cpio (no it's not R2D2's friend) is a copy in-out program similar to tar. Can archieve in amnay formats including tar. Can operate in the following three modes.

Copy-out : used to create an archieve. List of files read from source and written to either specified or standard output.
Sources may include a text file, the outpu of the find command, output from the ls command or other sources listing files one line at a time.
Format: source | cpio -ocBv > [archive_filename]

Copy-in: used to extract files from archive. By default all files are copied from archive. You can specify using metacharacter patterns.
Format: cpio -icdv < archieve_filename

Copy-Pass: Copy files from one directory tree to another combining the copy-out and copy-in modes without using an archive

Switch	Effect
o	Create an archive using copy-out
B	Change block size to 5120 from 512 default
c	specify ASCII archive format
v	List files processed
t	Print list of input

Interactive Archiving
tar -wcvf [destination] [source] - before adding a file to the archive the user is prompted

Using other utilities to archive
compress - will reduce the size of a file by 40-50% and add a .Z to the file as an indication it has been compressed.
-v will estimate the amount saved by compression.

gzip will append a .gz extension and will shrink single or multiple files into a single flle whose size is lower than using compress.
gzip is used to unzip gzipped files
zcat is a utility used to view files in their natural state.

Bring it Back!
tar -xvf restores the entire contents of the source file or directory structure. You can restore portions of the tar file by indicating the path and file name you wish to extract.

copy-in recovery cpio -icdv < [archieve_filename]
-i extracts files using copy-out mode
d creates directories as necessary
tar -wxvf [destination] [source] restores interactively

You should always be root or equivalent to perform backups

If you are not root or equivalent you may see "tar: tarfilename: Permission Denied"
'Tar: Error is not recoverable: exiting now" is a catch-all that can mean anything from the file is corrupt to the tape drive is damaged"

HP ProCurve Networking CBT notes

Dr.Disk — Tue, 22 Apr 2008 09:52:16 CDT

HP offers a free CBT training course for HP ProCurve Networking. As I go trough the CBT I am taking notes and posting here. This is not preperation for certification and is included only for referecnce. It is a brief overview of networking. These are simple notes and in no way are designed to replace the CBT which you can access and download for free at:
http://www.hp.com/rnd/training/technical/primer.htm

Ethernet Topologies and Technologies

Dr.Disk — Tue, 22 Apr 2008 09:38:15 CDT

Target Points

Identify the features and benefits of a physical star topology
Identify key features of the Ethernet specifications
Identify key features of wireless technologies
Identify key features of WAN technologies

Networking: - sharing of information and services
3 requirements:

services - 2 devices with a need to share info
media - a path for communication
protocols/standards - the rules

Servers provide basic services:

file
print
messaging
application
database

Clients attach to these servers to gain access to services

Transport/Communication medium provides a path for data transfer (copper/fiber/radio)

Protocols - rules that allow information sent over the transport to be translated into meaningful data.
TCP/IP and ethernet are most common communication standards.

Tasks defined by protocols:

how bits are transmitted
how cables are arranged
number of devices per network
when a device can transmit data
how data is sent
how devices communicate
when messages are successfully transmitted/received
how unlike OS communicate

Purposes of a topology (the physical layout of cables and devices)

Transmit Bits
Physical network structure
Mechanical and electrical specs
Encoding and timing rules for packet transmission

5 types of topologies are (bus, ring mesh, cellular and star {the most common topology})

Bus Topology - original ethernet standard
Nodes attached to a common backbone.
Signals generated by any device heard by all other devices.
Created two problems:
Collisions
Cable break would create noise and break communication among all devices

A sample bus topology

Features and benefits of a physical star topology
Cable concentration device (hub/switch) connecting clients and servers via drop cables.
Hub - receievs and passes signals - unable to decode signals and simply amplified signal before forwarding
Repeater - Used to amplify signal for greater distances and reliability
A hub that amplifies signals is a multi-port repeater.
Switches - more common today as the concentrator.
Data must pass through switch to reach devices directly or indirectly connected to the switch.
Hence, a switch is also a multi-port repeater

A Very Basic Star Topology

NICs (Network Interface Cards) - change binary data of node to electrical or optical signals for transmission
Star topology supports both fiber and copper. Choosing a medium decision is based on cost of communication media, transmission speed and size of LAN (number of devices and distance between any two end nodes on the network.).

Basic Path - NIC => patch cable => wall jack => drop cable =>punch down block/patch panel => patch cable =>switch

*Ethernet Standard *
Robust, high speed protocol capable of speeds up to 10 Gbps over physical star topology.
Fiber has extended distances once limited to hundreds of meters to tens of kilometers.
Specifications of Ethernet define certain limitations on cable types, cable lengths and the arrangement of switches.

Two basic star structures:
Flat
Cascaded/Hierarchical

Three basic benefits of the Star topology:

ease of installation
no disruptions when connecting or removing devices
easy fault detection and component replacement

Identify key features of the Ethernet specifications

Identify key features of wireless technologies
Identify key features of WAN technologies

Section 3: The Linux Filesystem

Dr.Disk — Thu, 17 Apr 2008 09:00:36 CDT

Target Goals

Navigate the filesystem
Manage the filesystem
Maintain the filesystem

Navigating in the Linux Shell

Basic Commands

Command	What It Does
ls	lists files and directories
cd	moves through directory structure
mv	moves files and directories
cp	copies a file
rm	Deletes files and directories
touch	changes access or modification to a file
mkdir	creates directories

All objects in Linux are seen as files

The root directory is represented by a /
You are placed in your home directory by default
The current working directory is represented by a period
The parent directory is represented by a double-period

Changing Directories using CD

CD alone returns to home directory
CD [pathname] takes you to specified path
CD ~ [pathname] takes you to the directory relative to home directory

Viewing Directory Contents

You can use dir or ls to view directory contents

Common Uses of LS (use man ls to see more extensive listing of options)

ls -F	lists directories with a slash to end directory name
ls -R	provides long-format listing
ls -l	Recursively list subdirectories
ls -ld	Povides long directory listing of directory but not contents
ls -la	Prints out regular and hidden files in the directory

Wildcards

Metacharacter	Action
*	Matches any or no character
?	Matches single character
Set [ ]	Matches single character
Range [ - ]	Matches any single charcter in defined range

Managing Files and Directories

The default Linux filesystem is ext3

ext3 is built on the traditional ext2 (which provided fast access as well as rapid read and write times-but lacked journaling feature - records disk activity to speed recovery from improper shutdown)
reiserfs - Treats partition as one database, a balanced tree is used to store directories, files and metadata (which are stored near each other for rapid access)

Filesystem Info
All filesystems must be mounted before they are available using syntax: [device] [mountpoint]
The mount command attaches the filesystem on various devices to a single tree

Various paths to devices:
/dev/hda - 1st hard drive
/dev/hda1 - 1st partition on 1st hard drive
/dev/fd0 - 1st floppy
/dev/sd -1st SCSI disk
/dev/st - 1st SCSI tape drive
/dev/console - monitor
/dev/tty - other consoles

mount without options will display the device, mount point, type and whether it is read-write or read-only.
unmount is used to unmount volumes (if you are using a directory on a mounted file system you cannot unmount it)

Mounting DOS
mount -t msdos Create a directory in /mnt for each device you will mount

nvram lets you view and change values stored in non-volatile memory (requires 2.1x kernel with /dev/nram support)

To burn a CD on a mounted CD-R create a directory for the files and make an ISO image of the files using mkisofs and burn the CD using cdrecord

Automated mounting
use /etc/fstab to list file systems to be mounted during boot and unmounted at shutdown, it is automatically created or updated.

Directory Creation
mkdir [dirname] - command for creating directories. The dirname can include a path to another location. You may include multiple dirnames in one command to create multiple directories.

Filesystem maintenance
FSCK - no I didn't just swear!

System performance is improved because disk writes aren't executed until required. Multiple read requests to the same block are served by RAM. An update utility consistentantly flushes the dirty buffers to disk to help prevent damage to data in the event of system disruption.

shutdown - synchronizes synchronizes disk buffers and cleanly exits any running process

fsck is used to check and repair the filesystem integrity. If no problems occur the number of files, blocks used and blocks free are listed. If problems occur the system prompts for correctve actions.

FSCK codes

Code	Value
0	No errors
1	Filesystem errors found and corrected
2	You should reboot the system
4	Errors found, but corrected
8	Opperational error
16	Usage/syntax error
128	Shared library error

fsck -r /dev/ [filesystem] - interactively repairs the the [filesystem] inidcated.
Only repair one filesystem at a time.
Journaling
Metadata includes: file creation date; last file modification date; ownership (group and user), permissions, file size, file location

Journaling helps maintain integrity of system if file is being written during a crash.

Before making a file change journaling makes note of the intended change. Once the change is made, amn entry is made indicating if the change was successful.

So....
If the system crashes before a journal entry is made the original data is intact but any changes may be lost.
If the crash occurs during a disk write, the journal entry remains to indicate impending change so that upon successful reboot the entry is read and either the change is executed or rolled back to a previous state

Performance Issues

recovery time after failure
bitmap tracking of the filesystem
fragmentation

Journaling uses disk space efficiently by allowing data to be read and written faster for a variety of file sizes via dynamic space allocation.

2 common filesystems are ext3 and reiserfs

fdformat - performs a low-level format

setfdprm - sets the device type eliminating the need to specify device capacity when formatting disk

The Return of MKFS
mkfs - used to create the filesytem

Filesystems

Type	Definition
ext2	extended and most common LInux filesystem
ext3	updated ext3
romfs	ramdisk read only filesystem
NFS	Network File System - used to acces remote files on network
msdos	DOS-FAT filesystem

Creating any filesystem also creates a lost+found directory. When system crashes or improper shutdown occurs files and directories without a directory entry are reattached to the inode table and placed in lost+found upon reboot.

Announcements

Dr.Disk — Thu, 17 Apr 2008 08:05:57 CDT

Date Announcement
04/17/08 I had planned to have all my notes up by now but life has been hectic and it is taking longer than I planned. Please be patient as updates to the site should be coming more frequently.

Section 2: Getting to Know Linux

Dr.Disk — Mon, 07 Apr 2008 13:12:13 CDT

Target Goals

History and Development of Linux
Be familiar with the Linux Shell
Classify Linux documentation by type and use
Start and Stop the Linux system

Created in 1991 Linux is an OS with commands similar to UNIX

Linux is an open-source OS allowing for a low cost, easy licensing, easily customizable operation with excellent performance and stability.

However, there aren't as many applications and there is always overhead involved in switching operationg systems.

Cost
While free, there are other costs to consider:

maintenance and support
upgrading memory and other hardware
finding people with technical expertise to provide support

How Linux can be used:

Type of box	Use
Server	Host websites and files, can control and secure network traffic
Workstation	Desktops in the buisness environment
Desktop	Focused on home use

*Can also be used for a DNS, Router, Database Server, Software Development, Parallel processing and as a Gateway

Common Linux Distributions (distros):
Red Hat - www.redhat.com
Fedora Core - www.fedora.redhat.com
SuSE - www.novell.com/linux/suse
Debian - www.debian.com
Mandrake - www.mandrakesoft.com

The Linux Shell

The shell interacts with the OS by allowing users to input commands and ensure the kernel executes them.

Commands in this guide are highlighted in blue and italic

Types of Linux Shells:

Shell	Explication
Bash	Default - Has flexibility of C Shell in a Bourne environment. command = bash
Bourne	Original UNIX shell command = sh
C shell	Designed to support C language and provide more inteactive use command = csh
Korn	Combination of C (shell) and Bourne (syntax) command = ksh

Multiple shells can be open simultaneously. You can close the shell with exit or Ctrl-D. You can view open processes including shells using ps.

The command echo $SHELL will show which shell is established at login. (echo prints and follows the commad to the sceen)

The more command is placed in front of a file you wish to view one page at a time.

The head command is similar to more but only displays the first 10 lines of the file. Conversely, the tail command displays only the last 10 lines of a file.

Shell Commands

The command syntax in linux is command -option argument

Linux is case sensitive
Like DOS you can access previous commands with the up and down arrow keys
The Tab key can be used to complete a complex command
Pipes ( | ) allow you to send from one command to the next
; can be used to combine commands

Help and Support
Using man before a command will display a reference manual

Create your own support page by documenting everything you do!

Use system documentation collected in log files. By default logs are stored in the /var/log directory.

The --help command can be used to show a summary, usage and syntax of the command

HOWTOs - Documents describing in detail various aspects of the Linux OS.

HOWTOs can be found in /usr/share/docs and at http://linuxdocs.org/HOWTOs/HOWTO-INDEX/howtos.org

Info Pages can be accessed with the info [topic] command. These documents can be used to access online documentation and printed documentation. An * precceding text indicates that it is linked. Moving the cursor to the text and pressing enter will access the linked info. Other internal info commands include:
U - return to previous document
D - return to the top
Q - exit to command prompt.

LUGs - Linux User Groups

Start and Stop Linux

Init Runlevels
Init reads the /etc/inittabfile to create processes at boot and set the system Runlevel
You can change the Runlevel using telinit

Runlevel options
0 - Halts the System 1 - Single User Mode 2 - Multiuser Mode / without Network File System (NFS)
3 - Full Multiuser Mode 5 - GUI Interface 6 - Reboots System

Shuttng Down
shutdown - warns users and shuts down OS
Shutdown Syntax: shutdown [-t seconds] [-options] time [warning messages]
Switches

Switch	Function
-k	Sends warning but doesn't shut down
-r	Reboot after shutdown
-h	Halt after shutdown
-n	Shutdown without calling init (not recommended)
-f	Skip file system check on reboot
-F	Force file system check on reboot
-c	Cancel shutdown in progress

Booting Up
In Red Hat the default bootloader is LILO below ver 7.1; ver 7.2 and above it's GRUB

Rescue disks can be used as should the kernel become unbootable.
3rd party utilities (e.g., System Commander) can be used as a boot manager

CCNA Jumpstart

Dr.Disk — Mon, 07 Apr 2008 08:14:46 CDT

***This project has been placed on hold until the Linux+ notes are complete!***

I have begun preparing to take the CCNA exam and I am using a wonderful book called CCNA Jumpstart by Patrick Ciccarelli and Christina Faulkner. On the following pages you will find my cliff notes version of my own notes as I perpare for the exam. In no means do my notes replace reading the book. Go out and buy it! The book makes what on the outset appears to be a difficult task seem simple and straightforward.

I do not believe these note would constitute copyright infringement of any form; however, if I am contacted by the publisher or authors I will be happy to take my notes offline.

Chapter 1: What is Networking?

Chapter 2: Communication Models

Milestones

Dr.Disk — Mon, 07 Apr 2008 08:06:29 CDT

Just a place to post when things are getting done

Milestone	Target Date	Accomplished
Finish Section 2 of Linux+	04/07/08

Online Study Guides

Dr.Disk — Mon, 07 Apr 2008 08:02:38 CDT

This page should contain links to online sample questions and other helpful resources for various exam preperation.

See also: Assignments | The Syllabus | Announcements

Guestbook

Dr.Disk — Mon, 07 Apr 2008 07:55:32 CDT

Drop a comment or make suggestions

Section 1: Installing Linux

Dr.Disk — Fri, 04 Apr 2008 08:22:42 CDT

Target Goals

Know the requirements of a Linux installation
Be able to install Linux
Perform post-installation tasks

Installing Linux is linear and includes obtaining system information and documenting changes which ensures success and reduces risk of installation problems.

Installation Prep
Check for updates and HOWTOs in Linux's Hardware compatability list. The Linux HOWTOs are detailed "how to" documents on specific subjects.

A number of HOWTOs are available at www.tldp.org/HOWTO/HOWTO-INDEX/hardware.html#HW<Device>

Device	<DEVICE>
CD-ROM and DVD-ROM drives	CDROM
Hard Drives	HWHD
Modems	MODEMS
Printers and scanner	PRINT
SCSI	SCSI
Serial Port	SERIALPORT
UPS	UPS

Things to consider about hardware

Hard Drive	Number of devices IDE or SCSI Drive size Number of cylinders
Drive Controller	IDE or SCSI Manufacturer
RAM	Ammount
CD-ROM	IDE SCSI If other make note of make and model
SCSI adapter	Note make and model
Network Card	Note make and model
Mouse	USB, PS2, Serial (record its port)
Monitor and adapter	Make and model Chipset RAM ammount

Compatibility sites:
Red Hat - http://bugzilla.redhat.com/hwcert
Linuxquestions.org - http://www.linuxquestions.org/hcl/index.php
SuSE - http://www.hardwaredb.suse.de/index.php?LANG=en_UK
Linux-friendly hardware - http://www.linux.org/hardware

Different distrubutions of Linux are tailored to different CPU types (e.g., AMD 64-bit CPU won't work with 32-bit Red Hat

Distributor Testing
After testing a distribution, HCL's (hardware compatibility lists) are released for the supported version. These lists have been tested under specific conditions and should be used only as a guideline.

Gathering Information

Use the BIOS to create a hardware list
Manuals and manufactorer's websites are good resources
Devices may have info printed on them
If not using DHCP, have the TCP/IP information available

Install Method

Source	Use and Hardware Requirements
CD-ROM, Hard Drive	Requires a boot disk, bootable CD-ROM or PCMCIA driver disk
FTP, HTTP, NFS Image	Requires network driver or PCMCIA driver

Local Install-Fastest and doesn't matter if network fails
Network Install-Doesn't require CD-Rom or large hard drive

Disk Partitioning
FDisk is used to create and manipulate partition tables Syntax: parition device name followed by partition number

IDE drives = /dev/hda1 or /dev/hda2
SCSI drives = /dev/sda1 or /dev/hda2

Default Linux Directories

/bin/	/dev/	/etc/	/home/
/lib/	/mnt/	/proc/	/root/
/sbin/	/tmp/	/usr/	/var/

Repartitioning

Partiton using FDISk or use a partitioning device to resize existing partitions

Destructive - delete and re-create partition using FDISk

NonDestructive - Third-Party patitioning software that can change sizes of partitions without destroying data. (e.g., Partition Magic or Partition-it)

Partitionless - Red Hat Linux 7.0 allows trying Linux without a full install. It requires a Formatted DOS FAT partition with enough free space for a workstation install (it is a limited install and requires a boot disk each time)

FIPS - First nondestructive Interactive Partition Splitting program (free utility comes with Red Hat and is used to resize the FAT table)

Creates two partitions one you resize and one FIPS creates

Limitations

only works on DOS with 512 byte sectors
FIPS does not split 12 bit FATs (i.e. a partition cannot be below 4,085 clusters since it would require writing 16 bit FAT as a 12 bit.
Does not support extended partitions
Requires a free partition

Bootloaders

GRUB (Grand Unified Bootloader) - used by RedHat on x86 to install bootloader to MBR

GRUB load order = primary bootloader => secondary bootloader => OS
GRUB receieves instuctions from OS and transfers machine control to the OS
GRUB configuration - /boot/grub/grub.conf

Other Boot Loaders

Bootloader	Description
LILO	Boot from up to 16 different configurations (DOS, OS/2, NT, UNIX and LINUX partitions)
ELILO	EFI bootloader - FAT 32 filesystems and network booting via DHCP/TFTP
Loadlin	Requires users first boot DOS/Windows -- a "Logical reload" cuasing DOS to be completely overlaid with Linux
System Commander	3rd party bootloader/bootmanager. Controls boot environment, with boot manager and partitioning software
SysLinux	DOS based,similar to loadlin, not as general (used to simplify first-time Linux nstallation and create rescue disks)

Booting LILO
Two stages:

Moves itself into memory and sets up the stack
Loads the secondary bootloader and continues the boot process and displays LILO: prompt

Troubleshooting Failed LILO Process

LILO Display	First Stage Bootloader	Second Stage Bootloader	Description
L error	Loaded	Can't be loaded	A two-digit error code is displayed
LI	Loaded	Loaded but couldn't execute	Caused by a geometry mismatch
LIL	Loaded	Started but can't load descriptor table	Media Failure or Geometry Mismatch

Points of Interest
--LILO does not depend on a specific file system
--Can boot from multiple mediums
--Can be used as MBR (first sector of hard disk)

LILO config file = /etc/lilo.conf

Machine Purpose - what will the system do?

workstation
desktop system
server
Web Server with HTTP and FTP
Mail Server
Programming terminal
Database Sever
News Server

Unecessary services will slow the system down
Use custom insatllation to deviate from the standard workstation, desktop, or sevrer install
--provides freedom to pick and choose components
--if you install services you don't need stop and start in Red Hat in xinetd or /etc/rc.d using:

chkconfig -- command line to turn services off and on at different runlevels
ntsysv -- application to configure service activity at boot for each runlevel
Services Configuration Tool -- GUI services configuration tool

Red Hat can be installed as a workstation, server, custom (for flexibility) and as an upgrade

Install process simplified

Boot from CD
Setup keyboard and language preferences
Create and determine partition settings
Select bootloader
Configure NICs
Configure firewall
Set location information
Set root password
Select install packages
Switch CDs as necessary (particularly with Red Hat)
Remove CD and Reboot

Post Installation

Document the installation proceedure and any changes to setups, configurations, topologies, adn histories that will help you troubleshoot future issues.

X Windows
The graphical interface can be configured for hardware devices other components through the primary configuration file. Other options include settings for the monitor, video card, keyboard, pointing device and more.

A X Windows HOWTO can be found at http://en.tldp.org/HOWTO/XWindow-User-HOWTO/

Determine your Runlevel
Text Login Screen = level 3
GUI Login Screen = level 5

Virtual Desktops
Default configuration provides 4 desktops
Use Ctrl+Tab or Ctrl+F1-F8 to cycle through

Documentation via log files

/var/log/messages
/var/log/dmesg
/tmp/install

Chapter 2: Communication Models

Dr.Disk — Thu, 20 Mar 2008 14:43:58 CDT

The Purpose of the OSI model and its seven

Review Questions Chapter 1

Dr.Disk — Thu, 20 Mar 2008 10:58:51 CDT

1. Why was AT&T given a monopoly over local phone service?

Because the government was convinced that having a single entity could provide more stable and reliable service to all US homes.

2. What was the significance of the Carterphone case?

It allowed devices not owned by AT&T to be added to their networks.

3. What government agency developed ARPAnet?

Department of Defense

4. What important invention was created by Robert Metcalf?

The Ethernet protocol

5. What are the four main characteristics of a LAN?

Installed in small localized areas
Interconnected devices using LAN specific equipment
Fast speeds
Devices have equal access to network resources

6. When would a MAN be used?

When connecting multiple inner city LANs

7. Describe how WAN's are different from LANs and MANs.

WANs are slower but more far reaching than LANs and MANs. They rely on existing telecommunication devices (such as leased lines or sattelites).

8. What are two reasons why ARPAnet and later the Internet were successful?

1. Reliable even in situations with partial failure
2. Distribution of BSD UNIX allowing universities to connect.

9. What network added to the overall capacity of the internet, and in what way?

The National Science foundation created the backbone for the internet.

10.What is one of the major accomplishments of Internet 2?

Gigabit speed

Chapter 1: What is Networking

Dr.Disk — Thu, 20 Mar 2008 10:31:47 CDT

Networking Basics:

A network is a group of interconnected devices (computers, printers, peripherals, etc) that allow for the sharing of information and resources between senders (source) and receivers (destination computer)

node: a device capable of communicating on a network

Devices connected by cables (copper, glass, plastic, radio wave and microwave transmissions.

internetwork: two or more devices connected together and communicating
--internetworking: ability of different networks to communicate using special hardware and software making it possible for two networks to communicate even when using different protocols.

Types of Networks:

LAN (local area network)

Characteristics:

good for small areas
high speed comminication - 10 Mbps or faster
provide access for multiple devices
use LAN specific equipment (repeaters, hubs and NICs

LANs lower equipment costs by centralizing resources and maintain security of information. Can be used to enhance collaboration and provie training via audio and video streaming.

A LAN is designed to connect nodes so they may share resources.

Due to limitations in distance, performance and manageability a LAN is typically confined to an office or building.

Hubs and switches are central devices that are interconnected via cables to allow data transmission to pass between network nodes.

Wireless LANs use access Access Points (APs) to transmit and receive data.

Bridges and Routers are used to interconnect LANs.

Network Interface Cards (NICs) -allow communication among devices.

MAN (metropolitan area network)

Characteristics:

Sites dispersed across city and surroundings
communication speeds of 100s of Mbps to gigabit speeds
Single point of connection between LANs
Use routers, telephone and ATM (Asynchronous Transfer Mode) switches and microwave antennas.

Constitute LANs interconnected across a city.

Very expensive but much faster than WANs. Offer better speed because of high-end cable and equipment.

Typically have one connection between sites due to cost of purchasing existing cable from telecommunication companies or having new cable installed.

WAN (wide area network)

Characteristics:

Cover large geographical areas (can be gobal)
Slow communication speeds
Access is limited (one WAN link shared among all LAN devices)
use routers, modems and WAN switches for communication

Wide Area Network (WAN) -connects two or more LANs (or MANs) over slow connections leased from phone company.

Global connections require satellite connectivity.

WAN speed is between 56Kbps and 1.5 Mbps (though 45Mbps is possible)

The internet is one big WAN!

CAN (campus area network)

A specialized network providing services through high-speed fiber connections between buildings with more than one LAN

Public Telephone System

Public Switched Telephone Network (PTSN) - comprised of several interconnected telecomunication companies.

Hush-a-Phone & Carter Electronics court cases ended AT&Ts monopoly. In 1966 the FCC ruled that devices not owned by AT&T could be attached to the telephone network.

Origins of First Networks:

First networks were mainframe systems running over dedicated lines

Semi Automatic Ground Environment (SAGE) developed in 1958 to link goverment computers at radar stations in US and Canada

Compatible Time Sharing System developed on IBM mainframe in the 1960's at MIT allowing users to run tasks at the same on the same system. Later used modems to connect over dedicated lines internally (user dialed number to access system) and eventually spread campus wide and even some remote home access.

Network Communication

Early networks were large, expensive and difficult to use, relying on terminals to process requests to mainframes before another terminal could make a request.

The 1970s saw the advent of communication protocols including Token Ring, ARCNET and Ethernet)

Ethernet being the most significant as it became part of the packet switching necessary for ARPAnet and ALOHAnet networks
ARPAnet Advanced Research Projects Agency (ARPA) of the US Department of Defense developed an experimental network created as a communication solution capable of withstanding a bomb attack. Also provide collaboration methods fo universities and government using e-mail. Disolved in 1989 leaving behind a public structure known as the internet and renamed the military system DARPAnet (Defense Advanced Research Projects Agency network).

The Internet:
Developed from the success of ARPAnet which provided reliable service even with partial failure and the distribution of BSD UNIX (an operating system allowing universities to access ARPAnet). Internet gained support with the birth of NSFNET (National Science Foundations linking of five universities) This would become ARPAnets backbone allowing interconnection of more networks.

NSF decomisions backbone in 1995 leaving the internet intact as a self-supporting industry.

Internet 2 is a very high performance Backbone Network Service (vBNS) and is being developed to support research and communication needs of Academic Institutions. 95 sites are linked by 12 regional gigabit Points of Presence (gigaPOPs).

Type	Result
g	move left one character
j	move down one line
k	move up one line
l	move right one character
^	Move to beginning of current line
$	Move to last line in file
:[number]	Move to line specified by number
w	next word
b	previous word
e	move to end of current word or next word if already at the end of a word
Ctrl+U	Move up 1/2 screen
Ctrl+D	Move down 1/2 screen
Ctrl+F	Move down one full screen
Ctrl+B	Move up one full screen

Date	Announcement
04/17/08	I had planned to have all my notes up by now but life has been hectic and it is taking longer than I planned. Please be patient as updates to the site should be coming more frequently.

0 - Halts the System	1 - Single User Mode	2 - Multiuser Mode / without Network File System (NFS)
3 - Full Multiuser Mode	5 - GUI Interface	6 - Reboots System