New Generation IT

Understanding of Basic Windows Services

2012-11-16T20:12:00.002-08:00

Improve performance by disabling Windows 7 services

Windows 7 loads many services at startup, most of them are essential for the core system features. By disabling unnecessary services, the performance can be improved significantly, especially on computers with low system resources. The command SERVICES.MSC in the search field of the Start menu will start the management console to tweak the services (the management console is also available by Administrative Tools in the Control Panel, option Services). In the management console, a description of each service is shown, including the relationship (dependencies) between the different services.

Disabling services

The specific description for each service is shown in the left pane. This information can be of use, if you are not sure if it is safe to disable a service. Because there are many services and the description is not always clear, it can be time consuming to find out which services can be disabled safely, and which services better stay as they are. For some services, the effect is even unpredictable which will result in strange future problems.
By double clicking a service, the tab General opens with a description of the service and the current start up settings. Most services have Manual (started only if needed by a program) or Automatic (started by Windows) as startup type. The startup type Automatic (Delay Start) is a special startup type which makes sure the startup process of Windows is not delayed by loading these kind of services. Services with the startup type Disabled won't run at all, even if a program needs the service. In most cases a strange error message is shown by the program which does not seem to relate to a disabled service. The tab Dependencies gives information about which other services the service depends on and which other services depend on the service. It is obvious not to disable a service if other services depend on it.

ATTENTION: After the startup of Windows some services with the startup type Automatic are disabled automatically to save system resources if the service is not needed anymore.

TWEAKING SERVICES WITH MSCONFIG?

Services can be disabled with the tool MSCONFIG (tab Services) as well. However, this is not the place to tweak the services! Use the Management Console to make changes in the settings of the services. It is also safer because it is not possible to disable essential services.

Disabling services to recover system resources

The list below shows multiple services which are reasonably safe to disable. But remember to read carefully the service description before disabling a service! Keep in mind that possible future error messages can be created (and solved...) by changing the startup type of the services. If there is any doubt about the effect of disabling a service, rather keep it unchanged! If certain functionalities don't function properly anymore, just reactivate the service by changing the startup type to Automatic or Manual. Do not disable to many services at once, but take some time to investigate the individual changes and do not disable services where other services depend on! If you hesitate disabling a service permanently, change the startup type to Manual first.
Adaptive Brightness: This service can be disabled when the monitor doesn't support detection of ambient light with sensors to adjus the display brightness depending on the lighting conditions.
Application Experience: Investigates the compatibility of older programs and searches for updates for known problems. Although disabling this service doesn't have negative side effects, it is better to keep it unchanged.
BitLocker Drive Encryption Service: This service can be disabled when BitLocker is not used to encrypt files (and a secure startup of the operating system).
Bluetooth Support Service: This service is only useful when there are devices which are connected by Bluetooth.
Computer browser: Tracks the computers (and files) on the network and maintains an updated list. This service is only useful in case of a LAN where the computers share files with each other. After disabling this service, it is still possible to browse the network. The service depends on the services Server and Workstation.
Desktop Window Manager Session Manager: Necessary for the new Aero Glass-interface. Only disable this service if the new Aero Glass-interface is not used.
Diagnostic Policy-service and Diagnostic System Host: For the detection of problems, troubleshooting and presenting known resolutions for Window components. If there are no problems expected anymore, it is safe to disable the service.
Disk Defragmenter: This services provides (automatic) defragmentation of the partitions. When this service is disabled, disable the defragmentation task as well (control panel, item Administrative Tools, Task Scheduler, Task Scheduler Library, Microsoft, Windows, Defrag).
Distributed Link Tracking Client: Makes sure that linked files on multiple computers in a network stay linked. This service can be disabled safely, because in most home situations, this option is not used at all.
Encrypting File System (EFS): Provides encryption of files on NTFS partitions. It is safe to disable this service when encryption is not used.
Function Discovery Provider Host: Enables sharing files over the network with other computers. If this service is disabled, the shared files are no longer visible by other computers in the network. Disabling this service is also possible by disabling the option Network discovery in the Network and Sharing Center in the Control Panel.
Function Discovery Resource Publication: This service publishes the shared files and printers so they can be discovered by other computers in the network. Disable this service if it is not necessary that other computers are able to discover shared resources. This service can be disabled as well by disabling the option Network discovery.
HomeGroup Listener and HomeGroup Provider: Services for sharing personal files using the HomeGroup. When the HomeGroup is not used, both services can be disabled.
Human Interface Device Access: Support for a multimedia device like a remote control and hot buttons on keyboards (like the volume and e-mail button).
Internet Connection Sharing (ICS): For sharing the internet connection with other computers in the network (this computer operates as a router). If a router is used to connect all the computers to the internet, this service is not needed.
IP Helper: Support for an IPv6 connection over a IPv4 network. IPv6 is the new connection type of the future which makes it possible to give every computer connected to the internet a unique IP address instead of one single IP address for the internet connection (where the connected router uses special IP addresses for home use). The use of IPv6 has some advantages (but also disadvantages) but at the moment, there are not many providers supporting this new connection type. If IPv6 is not supported or used, disable the service for security reasons.
Network List-service and Network Location Awareness: Without these services, the network connection still works fine, but it is no longer possible to show the status in the system tray and the Network and Sharing Center. To keep this functionality, it is better not to disable these services.
Offline Files: Makes the network shares also available when the share is offline. The edited files will be synchronized automatically the first time the network share has become available. If this option is not desired, then it is better to disable this service.
Portable Device Enumerator Service: Enforces group policy for removable mass-storage devices. If this service is disabled, it is no longer possible to read/write protected devices. If it is not necessary to access removable mass-storage device using group policy, it is safe to disable the service (the removable media will still be accessible by applications which don't rely on this service).
Remote Access Connection Manager: Necessary for managing dial-up and virtual private network (VPN) connections. If the computer is connected to a router and no VPN connection is needed, this service can be disabled safely. Because the service Remote Access Auto Connection Manager depends on this service, it can be disabled as well.
Remote Desktop Configuration, Remote Desktop Services and Remote Desktop Services UserMode Port Redirector: Services needed for Remote Desktop, when Remote Desktop is not used it is safe to disable these services.
Remote Registry: Thanks to this service, external users are able to make changes to the registry keys over the network connection. This option is not safe, therefore it is better to disable it.
Routing and Remote Access: Disable this service if it is not desired that other computers are able to dial in to get access to the local network.
Server and Workstation: Necessary to share files and printers with other computes within a network. If this is not the case, it is safe to disable these services. After disabling the services, it is still possible to access shared folders on other computers. If these services are disabled, it is no longer possible to activate the option File and printer sharing in the Network and Sharing Center, task Change advanced sharing settings.
Shell Hardware Detection: This service starts the auto play of devices like DVD drives and memory cards. This service is also responsible for showing a window with the options which action to take with a certain type of file. If you don't like this function, disable this service. Because the service Windows Image Acquisition (WIA) depends on it, it has to be disabled as well.
Tablet PC Input-service: Enables the Tablet PC and ink functionality. If the computer is not a Tablet PC, it is safe to disable the service.
Task Scheduler: It is not possible to disable this service. That's no problem, because the most scheduled tasks won't run if the computer is actively used by the user. The settings of the scheduled tasks can be changed by the Administrative Tools in the Control Panel, Task Scheduler. The possibilities to add and change tasks have improved significantly compared to Windows XP.
Themes: Disable this service if there is no need for the visual effects like the new Aero interface. Disabling is only advised for slow computers because the new interface is one of the most important reasons to upgrade to Windows Vista or Windows 7. To disable visual settings manually, go to System in the Control Panel, Advanced system settings (in the left task pane), tab Advanced, button Settings (sub Performance).
Windows Audio and Windows Audio Endpoint Builder: Keep these services enabled to be able to hear the audio effects.
Windows Biometric Service: This service is used for capturing, comparing, manipulating and storing biometric data (like finger prints or iris scan).
Windows Defender: Additional scanning software for unwanted, malicious software. When Windows Defender is turned off (control panel, item Windows Defender, option Tools, link Options, task Administrator), the startup type is set to manual automatically. If this service is disabled, Windows Defender can no longer be opened by the control panel!
Windows Error Reporting-service: Generates an error message when a program no longer responds. If this service is disabled, error reporting is no longer possible and existing solutions are not delivered anymore.
Windows Firewall: If a software firewall is installed, the Windows firewall is no longer needed. For safety reasons, it is better not to disable it.
Windows Image Acquisition (WIA): For transferring images from a scanner or camera to the computer.
Windows Media Player Network Sharing-service: If it is not desired to share Windows Media Player libraries, it is safe to disable this service.
Windows Search: Provides content indexing (like personal files and e-mail) to speed up searching this content. Disabling this service will slow down the search process to a file by file search. Indexing takes place in the background at a moment the computer is not used, for this reason it is not necessary to disable the service.
Windows Time: For automatically synchronizing the time and date. If it is not essential that the shown time is correct, disabling the service is no problem.
WWAN AutoConfig: Service for connecting the computer to a network (internet included) by a mobile broadband service like GSM and CDMA.

Other services

It is advised to keep the services which are not mentioned on this page unchanged.

Hope this is Informative for you :)

Learn How to speed up your system's Boot up time

2012-05-05T10:01:00.003-07:00

Top 10 Ways to Speed Up Your Computer’s Boot Time

If there's one thing everyone dreads, it's rebooting their computer. It may only take a minute or two, but it can seem like forever. Here are our top 10 tweaks that'll make your computer boot a little faster.

This is a pretty controversial topic, as there are a lot of startup-tweaking myths out there. So, we took to the streets (of the internet) and searched for as many easy, well-supported tips as we could find. There may be others, some of which are controversial, but these 10 things are almost sure to get you a faster-booting machine.

10. Tweak Your BIOS

When you first set up your computer, your BIOS is set up to make things a bit more convenient for you, but once you're all set up, those things can be disabled. If you hold the DEL key when you start up your computer (or whatever key your BIOS tells you to enter setup), you can turn on the "Quick Boot" option and move your hard disk to the top of the boot priority list. The Quick Boot setting will turn off the tests your computer runs when it first turns on, and the boot priority tweak will tell your computer not to look for CDs, thumb drives, or other media when it first starts, which will get you booted into your OS quicker. If you ever need to boot from CD though, you'll have to go back into the BIOS and change this again before you do.

9. Clean Out Programs that Launch at Startup

One of the most tried and true ways to speed up your boot process is to keep unnecessary programs from starting up with your computer. You can do this by running msconfig from the Start Menu's search box, and going to the Startup tab. This applications list will tell you what each of those applications does, so you know which ones you can disable and which ones you don't want to.

8. Delay Windows Services That Run at Startup

Many people argue that disabling Services from msconfig will also speed up your boot time, but we've found that this is more problematic than anything. However, you can delay certain startup services so that your computer boots quickly and then worries about them later—after all, you don't need all those services the minute you start up your machine.

7. Change Your Boot Menu's Timeout Values

If you're dual-booting your machine, then your boot menu probably has a "timeout value", meaning the amount of time it waits for you to make a selection before it just boots into the default OS. On Windows, this timeout value is often 30 seconds, which is a long time to wait if you aren't looking directly at your screen. To change this timeout value, head to msconfig and click on the BOOT.INI tab, and change the number in the timeout box to something lower. If you're dual-booting with Linux, you're probably running the GRUB boot menu, and you can change the timeout on that too.

6. Disable Unused Hardware

Your computer loads a lot of drivers when it first starts up, some of which you might not even use. Head into the Device Manager from the Start Menu's search box, and look for anything you aren't using—Bluetooth controllers, modems, and virtual Wi-Fi adapters are common culprits. Right-click on the entry you want to disable and hit "Disable". Remember to only do this with things you don't actually use—if you use Wireless Hosted Networks, you'll need to keep those virtual Wi-Fi adapters enabled. It's also worth mentioning here that keeping all your drivers up to date will help this portion of the startup time, too (which you can do with the help of a program like previously mentioned Device Doctor).

5. Keep Your Antivirus Running and Up to Date

This should go without saying, but we'll say it anyway: install some antivirus software, keep it up to date, and run a regular scan. This is more of a preventative measure than an actual boot-speeding tip, but if you ever do get malware, it's sure to slow your computer's boot time. With a good antivirus around like Microsoft Security Essentials, you'll be more protected against that happening. Don't like MSE? There are some great ones out there too, so there's no reason not to have one around.

4. Remove Unnecessary Fonts

Since the dawn of time, Windows has loaded fonts at startup and slowed down the boot time. This is less of a problem than it used to be, but it can still slow you down a bit. Windows 7 loads over 200 fonts at startup; even more if you've installed Microsoft Office. Chances are, you use very few of those fonts, so you can hide them to speed up that process. In Windows 7, open up the Fonts folder from the Start Menu's search box, and check off all the fonts you don't need. Then click the "Hide" button in the toolbar. This way, if you ever want them, you can bring them back, but Windows won't load them at startup. Note that just removing a few fonts probably isn't going to make a noticeable difference—you'll probably need to get rid of a few hundred. That said, you might have hundreds more fonts installed than you realized, so that isn't as ridiculous as it sounds.

3. Upgrade Your RAM

Installing more RAM has always been an effective way of speeding up your computer, and that hasn't changed. RAM is pretty cheap these days, so if you're running low, there's no reason not to stock up and make your computer run a little smoother. We've gone over how to replace it in both a desktop and a laptop, and even for the inexperienced, it's a pretty simple procedure.

2. Give Your Computer a Static IP

When you first start up your computer, it spends a significant amount of time asking the network for an IP address. You can get rid of this process altogether by giving your computer a static IP address that never changes. Not only does this make your network easier to manage (since each computer will always have the same IP address), but it can shave a bit more time off your startup. Here's how to do it in different versions of Windows.

1. Install a Solid State Drive

These days, your hard drive is probably the biggest bottleneck in your machine. One of the best upgrades you can make to your computer is to install a solid state drive, which has super-fast read times that can speed up your startup considerably. They're certainly not a cheap upgrade, nor are they without their own maintenance requirements, but if you want to speed up your computer and its boot time, you can't go wrong by installing an SSD. The difference will be shocking.

There is a way to look out boot Time

2012-05-05T09:49:00.002-07:00

Find your computer's boot time in Windows 7

Curious about how long it actually takes your PC to boot up (other than when you're in a hurry)? Here's how to find out.

Anyone who's owned a computer for an extended period of time (1+ years) can tell you that, after some amount of time, it just seems to boot up much slower than when they first got it. There are plenty of ways to help keep your computer's boot time as small as possible, but how can you find out exactly how long your system is taking to boot up? Check these steps out to find this information built right into a Windows utility.

Step 1: Open the Start menu and type Event viewer into the Search box and open the application.

Step 2: In the left pane of the Event Viewer, navigate the folders to Applications and Services Logs/Microsoft/Windows/Diagnostics-Performance.

Step 3: Expand this entry and double click on Operational (it should be the only thing in this folder) to see a full diagnostic report of your computer's operation.

Step 4: Click Filter Current Log in the pane to the right. In the window that appears, change "<All Event IDs>" (the text box above the one labeled Task category) to "100." Click OK to apply the filter.
The list in the center pane will now show information about each boot process.

Step 5: Select a specific event to see more information about that particular boot sequence.
For total boot time: Look in the pane that appears below this list; the value next to "Boot Duration" is the amount of time (in ms) that your system took to load from start to finish. Just divide by 1000 to get the time in seconds.

Keyboard Tricks in Windows 7

2012-04-19T01:15:00.001-07:00

Hi there,

Let me tell you Some of the cool tricks of Keyboard button which will help you to work more cool and faster in Windows 7. Here we go with some shortcuts button to impress your friends :)

So Lets Begin...

[Windows] + [D]	Show or Hide the desktop

[Windows] + [Home]	Minimize all but selected window. Reverse by clicking the key combination again.

[Windows] + [Spacebar]	Make all open windows transparent to view gadgets and icons on desktop.

[Windows] + left arrow OR right arrow	Dock selected window to the left or right half of your screen.

[Windows] + up arrow OR down arrow	Maximized and restores the selected window.

[Windows] + [Tab]	Launch 3D representation of open windows and click [Tab] key again to flip through them.

[Windows] + [B]	Puts focus on the ‘show hidden icons’ button on the system tray.

[Windows] + [1] To [Windows] + [9]	Launch first through ninth icon on taskbar, including items pinned to taskbar.

[Windows] + [SHIFT] + [1] To [9]	Starts new instance of respective taskbar icon.

[Windows] + [Alt] + [1] To [9]	Opens jump list for respective icon.

[Windows] + [T]	Move focus to front or back of taskbar.

[Alt] + [Ctrl] + [Tab] + left/right/up/down	Flip window.

[Alt] + [Tab]	Cycle through open windows.

[Windows] + [P]	Select the Projector Mode

[Windows] + [+] OR [Windows] + [-]	Activates Windows Magnifier to zoom in or out of screen.

[Ctrl] + [Alt] + [D]	Switch to docked mode.

Ctrl] + [Alt] + [L]	Switch to lense mode.

[Ctrl] + [Alt] + [F]	Switch from docked or lens mode back to full screen mode.

[Ctrl] + [Alt] + [I]	Invert colors.

[Windows] + [Esc]	Exist magnifier views.

[Windows] + [G]	Cycle through desktop gadgets.

[Windows] + [X]	Launches Windows Mobility Center. Especially useful if you’re working on a laptop.

Hope You Like It.... :"

Troubleshooting Root Login Problems In Linux

2012-04-15T07:46:00.000-07:00

Root Login Problems

When we type username as “root” and password as “redhat” , system unable to login. In this case we need to trouble shoot this problem. Different case is to be considered.

Step 1 :

Start in single user mode and change the password:

#passwd root

Type password as ‘redhat’ and then restart the system , if problem still occurs do the

step 2:

We start the system with single user mode

#vi /etc/passwd

Check the following line

Root:x:0:0:root:/root:/bin/bash

Just check the first and last option, it should be root and /bin/bash

Case I:

If username is changed then do as follow

#username –l oldname newname

Case II:

If shell is changed to /sbin/nologin then change it to.

#usermode –s /binbash root

Before changing the shell, first check that /bin/bash exist in /etc/shells. If not then install the rpm of bash shell

#rpm –q bash

If problem still occurs do step Step 3

Step 3:

Check the file shadow find out if theree is a (!)mark at the starting of password entry. If present, remove it . (!) mark lock the password

Root:!$2gr………….

And also check the last three column, it should be blank empty ( : : :)

If problem still occurs do the Step 4

Step 4:

Sometime some attribute are set on the /etyc/passwd or /etc/shadow file, which make these two file write and append protected. If such attribute are present, we need to remove that.

Command to check the attribute

#lsattr /etc/passwd

#lsattr /etc/shadow

---------- /etc/passwd

Suppose attribute is set

---ai----- /etc/passwd

---ai----- /etc/shadow

In this case we need to remove the attribute

#chattr –ai /etc/passwd

#chattr –ai /etc/shadow

Note:

In order to add attribute (+) sign is used, to remove (-) sign is used. If problem still occurs then use the Step 5

If system shows message that ‘chattr’ and ‘lsattr’ command not found, we need to check the rpm if not installed . we need to install the rom

#rpm –q e2fsprogs

Step 5:

Open the file /etc/securetty file to check the entry of virtual console and tty entry

#vi /etc/securetty

Check the following entry

Console

vc /1

vc /2

vc/3

vc /4

vc /5

vc /6

vc /7

vc /8

vc /9

vc /10

vc /11

tty 1

tty 2

tty 3

tty 4

tty 5

tty 6

tty 7

tty 8

tty 9

tty 10

tty 11

if we remove any one line say tty1 then we cannot login at terminal 1 but we can login to another terminal. If we remove all these entry then we cannot login to any terminal. So in that case we need to make all these entry and again check for username and password

if problem still occur do step 6

Step 6:

Check the file /etc/nologin, if present remove this file. Then open the file

#vi /etc/rc.local

Check the entry /etc/nologin in the file if present remove that: in rc.local file only one entry is present

Touch /var/lock/subsys/local

If you find “ touch /etc/nologin” remove this line . even if we remove nologin file from /etc and if we restart, again the file will create . that is why we nned to remove the entry from /etc/rc.local file. If problem still accur then use Step 7

Step 7:

Check the permission for /etc/securetty file , it should be 600 (rw for user no permission for the group and other)

#ll /etc/securetty

If permission are changed we cannot login. So first change the permission

#chmod 600 /etc/securetty

Then login if problem still occur then do Step 8

Step 8:

Check the file /etc/pam.d/login

#vi /etc/pam.d/login

Check for following line

Auth required denied.so

Remove this line if present. If problem still present then check the following line

Account required pam_access.so

If this line is present, we cannot login through root, remove this line and along with this also check the file

#vi /etc/security/access.conf

Remove the following line from the bottom

-:ALL:ALL

If problem still occur so Step 9

Step 9:

If password is changing but still unable to login

Copy two file

#cp /etc/passwd- /etc/passwd

#cp /etc/shadow- /etc/shadow

Sometime we find that shadow file and its back file shadow- does’nt exist, in this case we need to generate the shadow file as

#pwconv

Step 10:

Sometime the password age expired then do the following to check the age

#chage –l root

If password age is expired

#chage root

In this

Account Expiration date : Change the date

#chage –E -1 root

In this case the root password will never expire.

Step 11:

If problem still occur then simply open the file /etc/pam.d/login

And make all the field as optional

Step 12:

Sometime attribute is set on /etc/shadow file, password age is expired ad the root permission is changed for command ‘chattr’

In this case first change the permission for ‘chattr’

#chmod 700 /usr/bin/chattr

Remove the attribute on shadow file

#chattr –ai /etc/shadow

And finally set the date for the password

#chage –E -1 root

Step 13:

Recover .bash file

All user has .bash file

.bash_history

.bash_logout

.bash_profile

.bashrc

If .bash file remove than can not any user accept bash like this [root@root~]#

Than use this command

Note: This command use for all user and all user’s home directory in /home

#cp /etc/skel/.bash* /root

Thanks...

Installing Redhat Enterprises Linux ,kickstart

2012-04-15T07:44:00.002-07:00

INSTALLATION:

Installation can be done either by CDROM , NFS, LAN, FTP

Partition type and its size

/ 10000MB

/boot 128MB

/home 1000MB

swap 256 MB ( 1.5 to 2 times more than RAM Size)

to check the RAM size do the following step

Ctrl+alt+f7

Then type the following

#cat /proc/meminfo

this command will display the size and other information regarding RAM

Ctrl+Alt+F7 to return to the installation mode.

Note:

While installation we have to make sure that firewall option should be disable

No firewall
Selinux disable

Following Package are needed at the time of installation.

Desktop

1. X Window

2. GNOME

Application

1. Text Editor

2. Graphical Internet

3. Text Based Internet

Server

1. Server configuration tools

2. Web Server

3. Mail server

4. DNS server

5. FTP Server

6. Network Server

7. Legacy Network Server ( in this select Telnet)

System

1. Administrative Tools

2. System tools

3. Printing tools

Max Space Needed : 6132MB

Min Space Needed : 681 MB

While Installing Redhat linux 4.0 WS with the help of NFS and FTP, we have to perform the following step

First we have to check the rpm of ftp/nfs

ftp : vsftp-2.0.1…….

nfs : nfs-utils-1.0.6……

Now copy the disk 1 of the Redhat linux into the folder “/var/ftp/pub”

Now copy RPMS of remaining CD’s (Disk 2,3,and 4) inside /var/ftp/pub/RedHat/RPMS/

Now we need to configure the exports file.

#vi /etc/exports

/var/ftp/pub 192.168.0.0/255.255.255.0(rw,sync)

save and exit

now start the service

#service portmap restart

#chkconfig portmap on

#service nfs restart

#chkconfig nfs on

Now Boot the new system from disk 1 of Redhat linux and type

Linux askmethod

Choose language : English

Keyboard Type : U.S

Installation Method : NFS Image

NFS Server name : 192.168.0.254

NFS Dierctory : /var/ftp/pub

And continue the installation

There is slightly change in case of FTP

In case of FTP:

Boot the system from disk 1 of redhat linux and type

Linux askmethod

Choose language : English

Keyboard Type : U.S

Installation Method : FTP

Then first mentioned your system ip address in order to identify itself in network

192.168.0.24

255.255.255.0

then mentioned the FTP server address as

192.168.0.254

255.255.255.0

mount point : pub ( as in case of FTP the default path is /var/ftp)

and continue the installation

Kick Start :-

Kick start is one of the automatic installation method. Before making kick start file we need to check the rpm

Rpm : system-config-kickstart

Kick start consist of installation wizard which we can configured for another system like general information, root password, package , set the language, keyboard type, network, installation type etc. then save the kick start with any name say nfsks.cfg under /root

Suppose we use NFS type then we have to mentioned

NFS Ip address : 192.168.0.254

Path : /var/ftp/pub

Now we have to edit the file nfsks.cfg by editing one line

Selinux-disable

Now we have to configure the file /etc/exports

#vi /etc/exports

/root 192.168.0.0/255.255.255.0(rw,sync)

/var/ftp/pub 192.168.0.0/255.255.255.0(rw,sync)

Now start the service

#service portmap restart

#chkconfig portmap on

#Service nfs restart

#chkconfig nfs on

#service dhcpd restart

#chkconfig dhcpd on

Now boot the new system by Disk 1 of RedHat linux

And type

Linux ks=nfs:192.168.0.254:/root/nfsks.cfg

And continue the installation

Thanks,

yum and Fdisk,Increasing the Size of Swap Partition In Linux

2012-04-15T07:42:00.001-07:00

YUM:-

Yum server use for install all linux package easely. Yum fine automaticaly all required library. Befor use yum first install yum RMP.

Server Site :-

Mount cdrom

#mount /dev/cdrom /mnt

#cd /mnt

#cd Server

install first FTP package

#rpm -ivh vsft* --aid --force

#rpm –ivh createrpo* --aid –force

#cd

Copy all RPM in linux partations

#cp -var Sevrer /var/ftp/pub

#cd /var/ftp/pub

#ll

#createrepo Server

Now create repo file for server

#vim /etc/yum.repos.d/anyfilename.repo

[any name]

name=abc

baseurl=file://var/ftp/pub/Server

enabled=1

gpgcheck=0

:wq

#yum clean all

Client Side:--

Create yum file in client side

[any name]

name=abc

baseurl=ftp://10.0.0.254/var/ftp/pub/Server

enabled=1

gpgcheck=0

:wq

#yum clean all

This command use for both side for install RPM package

#yum install rpmname*

#yum remove rpmname*

#yum update rpmname*

Fdisk:

Representation of Hard disk

/dev/hdx

/dev/hda : Primary Master

/dev/hdb : Primary Slave

/dev/hdc : Secondary Master

/dev/hdd : Secondary slave

Fdisk command is used to create a partition

#fdisk –l

Display the partition Listing

Creating Partition

#fdisk /dev/hda

Press(m for help): m

Some important switches are

D : delete partition

N : New

L : listing

Q : quit

W : Save and Exit

T : changed type

Press : n

l : Logical (5 or above)

p: Logical partition( 1-4)

Type l

First cylinder (Take as default): Press Enter

Last Cylinder or +size or +sizeM or +sizeK (….) : +100M

Command (m for help) : w

# partprobe

( to update the partition table without restarting the computer)

Now we need to format the partition

#mkfs.ext3 /dev/hdax

Where x is the number of partition that is newly created

Now we mount this partition

#mkdir /partx

#mount –t ext3 /dev/hdax /partx

#mount /dev/hdax /partx

To mount this partition permanently make the entry in fstab

#vi /etc/fstab

/dev/hdax /partx ext3 defaults 1 2

Increasing the Size of Swap Partition :-

There are possibilities that any time we can increase the size of RAM, at that time we need to increase the size of swap partition as per the increased size of the RAM.

There are two method of doing so

a. creating partition

b. Creating file

Creating Partition:

i. We have to create one partition of size say 200MB and change its type to 82 (swap type) . save and exit and then run the command “partprobe”

ii. Format the partition say /dev/hda9

#mkswap /dev/hda9

iii. Make the swap partition active

#swapon /dev/hda9

iv. to check the entry of swap partition

# cat /proc/swaps

If we want to make the permanent entry in fstab then

#vi /etc/fstab

/dev/hda9 swap swap defaults 0 0

Creating file

i. first make an empty file

#touch /swp

ii. Now we customize the size of the swap

# dd if=/dev/zero of=/swp bs=1M count=200

iii. Format the newly created swap file

#mkswap /swp

iv. Active the swap file

#swapon /swp

To check the entry of swap file

#cat /proc/swaps

If we want that automatically this swap file activate , we need to make the entry in /etc/ec.local

# vi /etc/rc.local

Make the following entry

Swapon /swp

Save and exit

Thanks,

rpm,Task Automation and Scheduling In Linux

2012-04-15T07:41:00.000-07:00

RPM (RedHat Package Manager):

RPM package contain the file and directories associated with specific application and program.

RPM namegenerally includes version, release and architecture for which it was build.

Zip-2.3-8.i386.rpm

To install RPM:

#rpm –i rpm_name

To Remove RPM

#rpm –e rpm_name

In order to remove those package which has dependency

#rpm –e rpm_name –nodeps

Switches used with RPM

-i or --install

-e or --erase

-U or--Upgrade

-F or --Freshen

we can install rpm by using

#rpm –ivh rpm_name

-I : Install

-v : Verbose

-h : Human view (Hash Sign)

To Upgrade RPM:

#rpm –U rpm_name

To repair any corrupted rpm package

#rpm –F rpm_name

To make any rpm query

#rpm –q rpm_name

To check all rpm of related pacakes

#rpm –qa |grep rpm_name

To check particular file associated with which rpm

# rpm –qf /etc/passwd

passwd file is associated with setup-2.5 rpm

To check the rpm containing which file

#rpm –ql rpm_name

this command will list all the file associated with particular rpm.

To get the information about the particular rpm.

#rpm –qi rpm_name

To Install any rpm forely

#rpm –ivh rpm_name –force

Installing dependent packages:

Suppose we have 4 rpm’s r1,r2,r3 and r4 , we need to install r4 but r4 depends on remaining rpm’s then we use this command.

To check any rpm’s query

#rpm –qa “sendmail*”

To check rpm’s of related service

#rpm –qa |grep bind

Task Automation and Task Scheduling:-

It is used to perform the task at particular time

Two command are used

a. at

b. crontab

syntax:

#at time

at>command I

at>command II

ctrl+D

Example:

#at 10:30

at>eject

at>eject –t

ctrl+D

Option used

#at now

#at now+5 minutes

#at now+5 hours

#at now+5 days

#at tomorrow

#at 10:30 july 16 2006

we can also restrict the user not to use the ‘at’ command. Restriction will be provided by root login with administrator.

#vi /etc/at.deny

inside this file we have to just mentioned the name of the user in order to restrict him not to use ‘at’ command.

Just save and exit form the file

By default all users are allowed to use ‘at’ command. ‘at.deny’ is default in system. We can also create a file ‘at.allow’ file. Once we create this file, now by default all users will be restricted to use ‘at’ command and only that user which have entry on ‘at.allow’ will allow to use the ‘at’ command.

Another method is to make an entry inside the ‘crontab’ file. Entry will be done by the root. Difference between these two method is crontab is used to perform the same task many times whereas job through ‘at’ command will be removed after the task has been performed.

Syntax: ( By root login)

#crontab –e

six field are listed

1 2 3 4 5 6

minute hour day of Month day of command

month Week

Example:

35 10 31 05 3 eject

36 10 31 05 3 eject –t

Minute : 0-59

Hours : 0-23

Day of Month : 1-31

Month : 1-12

Day of Week : 0-7

0 and 7 are Sunday

#service crond restart

#whereis eject

this command display the path of the command. It is better to use the full path of the command inside crontab instead of just the name of the command.

We can also make the entry as

35 10 * * * eject

36 10 * * * eject –t

In this case. These two jobs will be performed at 10:35 in every month.

Some command which are executed with ‘at’ or ‘crontab’ send their output to the user mail box. These command are executed on background and their output is transferred to the particular user’s mail box. In order to see the output of the command we use.

#mutt

This command will open the mailbox from where we check the output

Some of the switched used with the ‘crontab’

#crontab –l

List out all the job scheduled in crontab.

#crontab –r

Can remove the job from the crontab.

#atq : list the job number scheduled in at

#atrm jobno : to remove any job

Thanks ,

Aliases,default permission,runlevel,welcome message at time of login In Linux

2012-04-15T07:40:00.000-07:00

Aliases:

Aliases are shortcut names for large commands. If we have command that run often, but take a considerable amount of typing, we can reduce these to an aliases.

Alias c=clear

We can make a permanent entry of alias in .bashrc file

Type:

#vi .bashrc

alias c=`clear`

save and exit

Test your change by logging out, logging back and type the following

#alias

Default Permission:

The default permission for files is 666 and directory is 777. umask is used to withhold permission. Default root’s umask is 022. without a umask in effect, only file created will have 666 permission and directory will have 777. this means that anyone on the system will have read and write access to any file. A umask of 002 will result in file created with 664 permission and directory with permission 775.

Default umask on Red hat enterprise linux is 002. to change

#umask 022

umask is typically set by script run at login time. The next time you lig in umask will be set bask to your default unless you add command to one of your startup files such as .bashrc.

Run Level:

To check the run level we need to see the file /etc/inittab

#vi /etc/inittab

defaults run – level used by RHS are

0 : hault ( do not set init default to this)

1 : single user mode

2 : multi user mode without networking

3 : multi-user mode with networking

4 : unused

5 : X11 (Graphical)

6 : reboot

#runlevel : this command shows that in which run level you are at present

in init 3 runlevel, if you type command startx to go to the graphical mode then it will not ask you for password.

By default we have 6 virtual console (text mode), but we van increase or decrease the number of text mode simply by editing the file /etc/inittab

#vi /etc/inittab

line No 18 : id:5:initdefault

(we can change this value from 1 to 5 as per our need)

Line No 44 :

1:2345:respawn:/sbin/mingetty tty1

2:2345:respawn:/sbin/mingetty tty2

6:2345:respawn:/sbin/mingetty tty6

in these line if we add one more line the number of virtual console increase and if we remove one line , virtual console terminal decrease.

For adding

7:2345:respawn:/sbin/mingetty tty7

after editing this file we need to sane and exit

#init q : this command is used to activate the change made.

Welcome Message at the time of login :-

We need to edit the file /etc/motd

#vi /etc/motd

type any message which we want to display

“WELCOME TO www.rhceccna.blogspot.com”

save and exit

Now login to user and check message…

Thanks,

Redirecting Input /Output,Symbolic links,Checking Free Space In Linux

2012-04-15T07:39:00.000-07:00

Redirecting Input /Output:-

The standard Output of command , which normally display on the terminal can be redirected into a file. Similarly standard error, which normally display on the terminal can be redirected into a file.

Common redirection operator

> : command>file : output command to file

>> : command>>file : Append output of command to file

< : command>file : receive input from file

2> : command2>file : error from command to file

2>> : command2>>file : append

Example:

#find /etc –name passwd

this command will search for all file name passwd in /etc and its subdirectories

now we can redirtect the standard outpout

#find /etc –name passwd > output

output is a file where command output will be stored. Standard error is still displayed on the screen

#cat output

If the target file of the file redirection with > already exists, the existing file will be overwritten. To append data to an existing file use >> to redirect instead of >

#find /etc –name passwd >> output

Redirecting standard Error

We can redirect standard error with 2>

#find /etc –name passwd 2>errorfile

standard output is displayed on the screen , redirect further standard error, appending to the same file with 2>>

#find /etc/ -name passwd 2>>errorfile

#cat errorfile

Symbolic links:

A symbolic link point to another file. We can display the link name and the referenced file by ‘ls –l’

#ls –l pf

lrwxrwxrwx 1 root root pf->/etc/passwd

file type: l for symbolic link

the content of the symbolic link is the name of the file that is referenced

Syntax:

Ln –s filename [linkname]

Example:

Ln –s /etc/passwd password

There are seven fundamental file type

- : regular file

d : symbolic link

b : block special file

c : character special file

p : named file

s : socket

character special file are used to communicate with hardware one character at a time. Block special file is used to communicate with hardware a block of data at a time : 512 bytes, 1024 bytes, 2048 bytes

ls –l /dev |less { to check c and b files}

named pipe type of file that passes data between processes. It stores no data itself socket file are used for inter process communication.

Checking Free Space:

In order to check the free and usage space per file system and directory and each sub directory we have two command

the ‘df’ command reports on a per file system basis. It report total disk space , disk space used , disk space free

#df –h

-h : used multipliers such as G or M for gigabytes and Megabytes

The ‘du’ command reports the number of kilobytes contained by the items within a directory

#du –s

#du –h

-s : used to request only the summary directory information

#du –s /etc

Thanks,

Hard Link and Soft Link in Linux

2012-04-15T07:37:00.000-07:00

What is the difference between Hard Link and Soft Link in Linux?

Hard Link is a mirror copy of the original file. Hard links share the same inode.
Any changes made to the original or Hard linked file will reflect the other.
Even if you delete any one of the files, nothing will happen to the other.
Hard links can't cross file systems.

Soft Link is a symbolic link to the original file. Soft Links will have a different Inode value.
A soft link points to the original file. If you delete the original file, the soft link fails. If you delete the soft link, nothing will happen.
Hard links can cross file systems.




Lets learn the differnce with an example Example: Create a file " original-file.txt " :~/test$ echo "Learning about Hard and Soft Link" > original-file.txt :~/test$ cat original-file.txt Learning about Hard and Soft Link Now lets create a Hard Link Example: HardLink-file.txt :~/test$ ln original-file.txt HardLink-file.txt :~/test$ ls -il total 8 840388 -rw-r--r-- 2 telson telson 33 2009-05-18 09:16 HardLink-file.txt 840388 -rw-r--r-- 2 telson telson 33 2009-05-18 09:16 original-file.txt Now lets create a Soft Link Example: SoftLink-file.txt :~/test$ ln -s original-file.txt SoftLink-file.txt :~/test$ ls -il total 8 840388 -rw-r--r-- 2 telson telson 33 2009-05-18 09:16 HardLink-file.txt 840388 -rw-r--r-- 2 telson telson 33 2009-05-18 09:16 original-file.txt 840186 lrwxrwxrwx 1 telson telson 17 2009-05-18 09:23 SoftLink-file.txt -> original-file.txt From the above ls -il result, you find the same inode for " HardLink-file.txt " and " original-file.txt ". Inode value is different for the soft link " SoftLink-file.txt ". Now lets try editing the original file: Example: :~/test$ cat >> original-file.txt Editing this file to learn more!! :~/test$ cat original-file.txt Learning about Hard and Soft Link Editing this file to learn more!! :~/test$ cat HardLink-file.txt Learning about Hard and Soft Link Editing this file to learn more!! :~/test$ cat SoftLink-file.txt Learning about Hard and Soft Link Editing this file to learn more!! Now lets try changing the permissions: Example: :~/test$ chmod 700 original-file.txt :~/test$ ls -il total 8 840388 -rwx------ 2 telson telson 67 2009-05-18 09:34 HardLink-file.txt 840388 -rwx------ 2 telson telson 67 2009-05-18 09:34 original-file.txt 840186 lrwxrwxrwx 1 telson telson 17 2009-05-18 09:23 SoftLink-file.txt -> original-file.txt From the above example its clear that changing the permission of " original-file.txt " will update the permission set of " HardLink-file.txt ". The soft link remains unchanged. Now lets try deleting the original file. Example: :~/test$ rm original-file.txt :~/test$ ls -il total 4 840388 -rwx------ 1 telson telson 67 2009-05-18 09:34 HardLink-file.txt 840186 lrwxrwxrwx 1 telson telson 17 2009-05-18 09:23 SoftLink-file.txt -> original-file.txt :~/test$ cat HardLink-file.txt Learning about Hard and Soft Link Editing this file to learn more!! :~/test$ cat SoftLink-file.txt cat: SoftLink-file.txt: No such file or directory So removing the original file will affect the Soft link. The Soft link fails. Hard link is unaffected.

User And Group Managemen in Linux

2012-04-15T07:32:00.003-07:00

User and Group Administration:

There are three type of user account in Red hat Linux

Super user or Administrative account
Regular user account
service account

Super User created automatically at the time of installation
Regular user Account;

Using command line method ‘useradd’ or ‘adduser’ command
Graphical method by using Red hat user manager utility

# adduser user_name (Recommended : minimum 6 character used in password)

# passwd user_name

Example:

#adduser Deepak

#passwd Deepak

Now open the file /etc/passwd to check the entry of user

#vi /etc/passwd

it contain 7 entry of each user

Username
Password
userid
groupid
blank (User information field ) comment
home directory
login shell

password entry for each user will be stored in /etc/shadow

# vi /etc/shadow

now in order to check the Userid, Group we use /etc/login.def

# vi /etc/login.def

when any user account is created then user will get userid, groupid automatically from /etc/login.def

5^th field is used for user information or comment

6^th field is used for home directory. When any user is created its default home directory is created inside /home

/home/Deepak

7^th field is login shell. Default shell for user is /bin/bash

different shells are used

ksh, sh, csh, tcsh,zsh

shell is an user interface between user and O.S. linux command shell is a prompt that allow us to interact with our system by executing various command.

In order to check the shell available use /etc/shells

# vi /etc/shells

in order to get the information about the group we need /etc/group

#vi /etc/group

it contain four field

Group name
password
GroupId
Member of group

# finger : this command is used to get the information about the user

Syntax:

#finger username

#finger Deepak

#id : this command is used to get userid, groupid of the user

syntax:

#id username

#id Deepak

Creating Group:

Syntax:

#groupadd groupname

#groupadd –g gid groupname

Example:

#groupadd jeet

Exercise:

Create a user that should have uid=1000 shell=sh description and home directory as /data

Sol:

#useradd –u 1000 –c Deepakpundir –s /bin/sh –d /data Deepak

#passwd Deepak

Grpahically

System Setting :-> User & Group

#system-config-user

Every user have two group one is elementary group or primary group and secondary group

-g : Primary Group

-G : Secondary Group

Creating Group

#groupadd g1

#groupadd g2

Steps:

1. adding group to the user

#usermod –g g1 –G g2 Deepak

2. To change id of the user

#usermod –u 1001 Deepak

3. change comment

#usermod –c Deepakmehra

4. change home directory

#usermod –d /Deepak-home Deepak –m

5. change shell

#usermod –s /bin/bash Deepak

6. change user login name

#usermod –l newname oldname

#usermod –l jeetesh Deepak

7. Change Group name

#groupmod –n newname oldname

#groupmod –n group1 g1

8. change Group id

#groupmod –g 2005 group1

Thanks,

Use of text Editors in Linux

2012-04-15T07:31:00.001-07:00

vi, vim Editor:

Vi is the standard file editor for Unix and Vim is the standard file editor for Linux

For Red hat Linux vi and Vim both are same

There are three mode of vi editor

command mode
insert mode
save and Exit Mode

Command mode is again divided into 3 mode

Cursor movement
Copy, paste, delete, undo
Text search

a) Cursor movement:-

J : Down

K : UP

L : RIGHT

H : LEFT

b) Copy, paste, delete, undo:-

dd : delete particular line

yy : copy particular line

u : Undo

p : paste

ndd : n is the number of line to be deleted

nyy : n is the number of line to be copied

c)Text Search :-

/text

example

/then

2)Insert mode:-

Option I, insert, a ,o, O

i : insert mode start at the point where cursor is. Same is used with

insert option

a : insert mode start after one character

o : insert mode start after one line

O : insert mode start before one line

3) Save and Exit Mode:-

:q : Quiet

:q! : forcely quiet

:wq! : save and forcely quiet

:wq : save and exit

Thanks ,

Linux file system Simplified

2012-04-15T07:30:00.000-07:00

File system in Linux is as follows :

root : it is an home directory of super user (root) administrator

etc : it is the location of all configuration file and directory used for server

configuration or system configuration

dev : it is a location of the device file

home : it is a location of home directory or regular users

proc : it is a virtual file system or directory not actually store on the disk and

contain system information

# cat /proc/meminfo

# cat /proc/cpuinfo

boot : contain kernel and boot related files

sys : it is also a virtual directory and contain system information

media : it is a mount point of removable disk like cdrom floppy usb drive etc.

tmp : it contain all temporary file

usr : it is used for software installation

lib : it contain all library files

bin : it is the location of all executable files or command or user command

/usr/bin also contain user command

sbin : it contain all system command or super user command /usr/sbin

mnt : it is a mount point for physical hard-disk or partition

opt : optional directory and used for temporary working

var : it is a variable file system or directory and contain all log and error

message

File system type:

Dos : Fat 16

95/Xp/2000 : FAT32

Xp/NT/2000 : NTFS

Linux : EXT2,EXT3

UNIX : VXFS

Representation Of Media Devices::

All the device file are stored in /dev/

Hard disk ; /dev/hdx

Where x is

a : /dev/hda : Primary master

b : /dev/hdb : Primary slave

c : /dev/hdc : Secondary master

d : /dev/hdd : Secondary slave

In case of SCSI, Sata or USB we will use : /dev/sda

CD-rom:

/dev/cdrom

/dev/cdrom1

/dev/cdrecorder

Floppy:

/dev/fd0

/dev/fd1

to access partition of windows in linux

#mount –t vfat /dev/hdax /mnt

in order to check the label of any partition

#e2label /dev/hdax

where x is number

Thanks ,

Getting help,File and Directory Permissions In Linux

2012-04-15T07:27:00.000-07:00

Getting Help:

The command that are used to get the help are discussed as :

Whatis

Display a short description of command , it uses a database that is updated nightly. Often not available immediately after installation.

Syntax:

# Whatis cal

Help

Display usage summary and argument list

Syntax:

<command> --help

Example:

#Date –help

Man and Info:

Both provide documentation for command. Almost every command has a “man” page. Collection of pages are called linux manual.

# man date

# info date

Viewing Text Page

Syntax:

#less [option] [filename]

Example:

# less abc.txt

scroll with arrows/PgUp /PgDown

/text : search for text

n : Next Match

Option:

-c : Clear before displaying

-s : Squeeze multiple blank lines into a single blank line

Simply we can also use “less” along with pipe | as

# ll |less

File and Directory:

‘ll’ is used to display the information about the files and directory including date, time, users,group, size, name and permission.

Four symbols are used when displaying permission.

R : Read

W : Write

X : Execute

- : no permission

-rwxrwxrwx : files

drwxrwxrwx : directory

files and directory permission are symbolized by ten character.

If we want to change permission, then there are two methods:

symbolic

Numeric

1. Symbolic Method:

Syntax:

Chmod mode directory/filename

Mode Option:

u,g,o

w,r,x

+,-

# chmod u+rwx file or directory : in case of user only

# chmod ug+rwx file or directoty : in case of user and group

# chmod u+w,g+r,o+x directory/file

# chmod u+rw,g+rw directory/file

# chmod u-r, g-w,o-rw directory/file

# chmod ugo+rwx file/directory

# chmod ugo-rwx file/directory

+ is used to add permission

- is used remove permission

chmod ugo=rw directory/file

this command will assign read/write permission to u,g,o

suppose we have one file as

test.txt

permission : -r- - r- -r- -

chmod u=w,g=wx,o=w test.txt

this command will assign write to user, write/execute to group and write to other while remove the previous permission.

The main difference between +,= are + operator simply add the new permission with previous one and = assign the new permission while removing old (new permission overwrite an old)

2. Numeric Method:

In this method, calculation are based on following numbers

r = 4

w = 2

x = 1

0 = no permission

Example:

#chmod 777 file/directory

in this case user get 7 means that user has permission of read/write/execute, group get 7 means read/write/execute and ame for other

# chmod 531 file/directory

in this case user get 5 means that user has permission of read/execute, group get 3 means write/execute and other get 1 means that other has permission to execute.

#chmod 742 file/directory

7 : User : rwx

4 :Group : r

2 : Other : w

Thanks ,

Understanding Basic Linux Commands

2012-04-15T07:07:00.001-07:00

Mode of Login

There are two mode of login

Text Mode (Alt+ctrl+F1)
Graphical Mode (Alt+Ctrl+F7)

In case of Text Mode

Station2 Login : root

Password : redhat

[root@station2~]#

to switch from one text mode to another

Alt+Ctrl+F1 to Alt+Ctrl+F6

In case of Graphical Mode

Ctrl+Alt+F7

Common Commands

Some of the Common system command are as follow:

1. Date : to display date and time

2. Cal : to display the calendar

3. Cal 11 2006 : display the calendar of Month 11 and year 2006

4. Clear : To clear the screen

5. ls : to list directory contents

color identification

blue : Directories

White : Files

Green : Executable files

Red : Zip files, rpm, tar file

Different switches used with “ls” command

ls –l or ll : used for long listing including file and directory permission

(-) : file

(d) : Directory

(l) : Symbolic link

ls –a : shows all hidden files and directory. Any file followed by (.) is hidden file

ls –al : show all hidden files and directory with long listing or whole description

ls –d : shows all the directory

6. pwd: Print working directory

7. who am I : display the information of current terminal

8. who : display all the terminal in a network

9. history : it shows all the command your have used.

By default history stores last 1000 command which u have run. If u want to change

# vi /etc/profile

HIST SIZE =10

Save and exit

# history –c ( to clear all the previous command reside in history)

Creating file and Directory:

Creating file:

The ‘cat’ command is used to create a file

Syntax:

# cat > filename

example:

# cat > abc.txt

(Ctrl +D) is used to save the file.

View the content of file

Syntax:

# cat filename

Example:

#cat abc.txt

#cat –b abc.txt

Creating Directory

The ‘mkdir’ command is used to create directory

Syntax:

Mkdir [directory_name]

Example:

# mkdir jeet

Option used:

cd : To change directory

cd .. : To come out from directory

cd : to jump to root directory

cd - : to jump to previous directory

Deleting Files and directory:

Syntax:

For file:

rm <filename>

example:

rm abc.txt

for directory

syntax:

rmdir <directory_name>

Note: Only empty directory will be deleted)

If we want to delete the tree structure of directory then we need to use the following command

Syntax:

rm –rf <directory_name>

where

r = recursively

f= force

In order to remove non empty directory

Syntax:

rm –r <directory>

example;

rm –r jeet

this will remove directory step by step ,first remove sub directory and then finally main directory.

Another method of creating file :

Touch : this command is used to create a blank file with size zero.

# touch <filename>

Example:

#touch abc

Copying File and Directory:

Copy file:

Syntax:

# cp [source]filename [destination]

Copy directory

#cp –r [source]directory [destination]

to copy a directory into another directory recursively

cp –rf [source]directory [destination]

to copy a directory forcely

syntax used for copy file or directory:

cp [option] file destination

option:

-I : interactive : ask before overwriting file

-r : Recursive

-p : Preserve

-f : forcely

More than one file can be copied at a time if the destination is directory

Syntax:

cp [option] file1 file2 file 3 Destination

Moving and Renaming File and Directory:

Syntax:

# mv : move /rename files and directory

Example:

# mv [option] file destination

example:

# mv t.txt /home/jeet/

more than one file can be moved at a time if the destination is a directory

# mv [option] file1 file2 file3 destination

Thanks ,

Some Interesting Facts On LINUX

2012-04-15T01:44:00.004-07:00

Introduction To LINUX

2012-04-15T01:37:00.002-07:00

Unix is the first Operating system in the world, developed by Kem Thompson and Dennis Ritchie in 1969 at Bell Lab by AT&T Company

IBM : AIX

SGI : IRIX

HP : HP

Sun : Solaris

FSF:

Free software foundation organization, they start a project by name GNU. The mail aim of this project is to develop such a O.S that can run on any platform.

In 1991, a student Linus Tarvalds developed a kernel named Linus’s Kernel plus GNU application called Linux O.S

Linux is a open source technology.

Different companies that provide Linux in Market are Redhat, SuSe, Mandrake, Turbo, Knoppix etc.

Features and Advantage:

Features:

Linux is the fastest Operating system in the world. It runs 2 to 3 times fast than windows O.S
Linux is the very secured O.S because there is no any problem of virus.
Linux file format is text format and windows file format is binary format.
Linux is very reliable O.S because kernel of linux is very stable as compare to windows kernel not crashed easily.
Kernel of linux is vcery small, it can be stored in floppy
Linux uses the x-Window system which is advanced network windowing system. Using this system we can display output of any workstation monitor attached in the network.

Advantages:-

Virus Proof
Crash Proof
Economical
Multiuser, multi desktop and multi tasking.

Thanks,

Important Port Numbers You Should Know

2012-04-15T01:08:00.000-07:00

Nowadays networking is one of the most important parts of the IT business. Either way, if you have/want to block ports with a firewall/masquarading/tunneling, want to check for runnings daemons(/services) or something else, you may want a more comprehensive overview about these with some hints and remarks about the essential ports largely used, together with a statement, which protocol (TCP/IP or UDP) is used exclusively or mainly, than official RFC documents or modern /etc/services files on UNIX systems offer. Therefore I hope to provide you with some useful informations below.

Some general hints for the less experienced in these topics: the port numbers below 1024 are privileged ones, what means, that a server process (UNIX daemon) can be run only by the root user on it. A bunch of services is managed by the portmapper (rpc service) and the inetd, which launches other special daemons listed below, when requested on the corresponding port. And finally, you can easily discriminate between TCP/IP and UDP with the telnet client: typing telnet IPaddress (or hostname, if resolvable) port-number gives you usually a connect response, when there is a service available via TCP/IP, while not when it runs via UDP/IP, and this is also a possibility, to check for certain ports and therefore services on the given host.

port / protocol	service name	common UNIX daemon(s)	additional remarks
20/tcp and 21/tcp	ftp (file transfer protocol) data and login control	in.ftpd,wu.ftpd,proftpd; launched by inetd	obsolete:insecure, because unencrypted and difficult to harden service, please use sshd and scp or sftp instead (see below)
22/tcp	ssh (Secure SHell)	sshd	secure, because fully encrypted remote login (ssh) and copy (scp and sftp) service, please use exclusively this full substitute instead of the obsolete ftp, telnet, rlogin, rsh, rcp and so on!
23/tcp	telnet (remote login)	in.telnetd, launched by inetd	obsolete: unencrypted login, use sshd and ssh instead, see above
25/tcp	smtp (simple mail transfer protocol)	sendmail, postfix, qmail, etc.	standard mail protocol since 30 years, only way to communicate world wide with messages without http measures, for your privacy you need to encrypt mails preferably with the free PGP (pretty good privacy)
53/udp and 53/tcp	DNS (domain name system)	bind (Berkeley Internet Name Domain)	the name service of the Internet, used by http, smtp and all others to resolve symbolic names into the IP layer addresses, name resolution is done via udp, zone transfers between several name servers via tcp
80/tcp	http (Hyper Text Transfer Protocol) = www (World Wide Web)	httpd (= apache, A PAtCHy [web] sErver)	the Internet/web service, unencrypted port (see below, 443, for encrypted counterpart) for standard data transfer from web servers to user agents (browsers, robots, download tools)
88/tcp	kerberos	krshd	high security special purpose protocol with ticket system and so on
110/tcp	pop3 (Post Office Protocol version 3)	popper, launched by inetd	post retrieval service of storing mail servers with encryption possibilities
111/udp	(sun)rpc (remote procedure call)	rpc.statd, rpc.rusersd,rpc.walld	insecure remote calls of special information services
119/tcp	nntp (Network News Transfer Protocol)	leafnode	the internet news server query service
123/udp	ntp (Network Time Protocol)	(x)ntpd	modern world wide time service for synchronisation with nuclear clock driven time standard
137/udp	netbios-ns (NETBIOS Name Service)	nmbd	special name service for a still too widespread proprietary OS and its SMB (Server Message Block) system, needed in union with the following service
139/tcp	netbios-ssn (NETBIOS Session Service Network)	smbd (Samba daemon)	special session service for that proprietary OS and its SMB (Server Message Block) system, works together with immediately above service
143/tcp	imap2 (Internet Message Access Protocol version 2)	imapd (Interactive Mail Access Protocol Daemon), launched by inetd	rather insecure and therefore only locally suitable mail retrieval service, for non-local purposes prefer pop3 (see above)
161/tcp	snmp (Simple Network Management Protocol)	snmpd	base of communication between very different technical units (not only computers), they have to share the network capability and these protocol rules only: CAUTION: very insecure (no limiting of allowed requesting IP addresses possible)
194/tcp	irc (Internet Relay Chat)	ircd	the Internet chat service
220/tcp	imap3 (Interactive Mail Access Protocol version 3)	imapd	modern mail retrieval service, successor of imap2 (see above), but still pop3 may the better alternative (see above too)
389/tcp	ldap (Lightweight Directory Access Protocol)	ldapd	network distributed, domain organized directory service, connection part, see also immediately below
389/udp	ldap (Lightweight Directory Access Protocol)	slapd (Standalone Lightweight Access Protocol Daemon	network distributed, domain organized directory service, listener/contoller part, see also immediately above
443/tcp	https (HyperText Transfer Protocol Secure)	httpd (= apache)	encrypted (via TLS/SSL) counterpart to above http/80 entry, the only acceptable way, to do online credit card transactions
514/udp	system log listener	syslogd	always active to log other hosts informations, because otherwise the daemon won't start
515/tcp	print spooler	lpd (Line Printer Daemon)	network printer queue
554/tcp	rtsp (Real Time Stream Protocol)	rsvpd (Resource reSerVations Protocol Daemon)	used by Real Media for video and audio streaming
631/tcp	ipp (Internet Printing Protocol)	cupsd --- CUPS (Common Unix Printing System) Daemon	unencrypted port for (local) printer access via browser and CUPS client
744/udp	flexlm (FLEXible License Manager)	lmgrd (License ManaGeR Daemon)	network bound license evaluation system
901/tcp	swat (Samba Web Administration Tool)	swat, launched by inetd	browser/web bound Samba administration (see above, 137/nmbd and 139/smbd), use with care: it's not encrypted without additional measures
993/tcp	imaps (Interactive Mail Access Protocol Secure version 4)	imapd, launched by inetd	TLS/SSL encrypted mail retrieval system (see also imap above)
994/tcp	ircs (Internet Relay Chat Secure)	ircd	the Internet chat system TLS/SSL encrypted, see also irc above
995/tcp	pop3s (Post Office Protocol Secure version 3)	popper, launched by inetd	TLS/SSL encrypted mail retrieval system (see also pop3 above)
2049/tcp	NFS (Network File System by Sun)	nfsd, rpc.nfsd, needs (sun)rpc and portmap too	network sharing of filesystems, only suitable for local networks
2049/udp	NFS (Network File System by Sun)	rpc.mountd needs (sun)rpc and portmap too	network sharing of filesystems, only suitable for local networks
2401/tcp	cvspserver (Concurrent Version System Password server)	cvs, launched by inetd (alternatively by sshd, see above)	RCS (revision control system) based network version control, suitable even for Internet cooperation, but than usage via ssh (see above) is recommended, because this pserver protocol does only a not really secure scrambling of passwords (only suitable for anonymous checkout otherwise)
6000/tcp (--6063/tcp)	x11	X (X window system server)	standard GUI base server of the X/Open Group, the ports above 6000 up to 6063 are addressed via display (variable: upper case) setting to 1, 2 and so on, instead of 0, for the ports 6001, 6002 and so on instead of 6000 (display number part 1 = port offset)
8080/tcp	http-alt (alternative http)	httpd (= apache)	see http above: usually privately=non-public used http port

Thanks...

SUBNETTING AND IP ADDRESS TROUBLESHOOTING

2012-04-15T01:02:00.001-07:00

SUBNETTING:

It is also called sub networking. It is a process through which a very large complex network is sub divided into smaller parts and each such part is known as subnet or sub network.

Benefits

Ø Reduce network traffic load

Ø Easy to manage and troubleshoot

Ø More chances of expansion

192.168.10.0./26 this is class C network address.

1. identify the valid no. of subnets

§ 2ⁿ

§ Where n is the no. of the borrowed bits

§ In above case subnet is 26 bit i.e. 2 borrowed bits for class C it must be 24.

2. identify valid no. of hosts for each subnet

§ 2^m-2

§ Where m is remaining host ID portion bits.

§ Here 2 bits are borrowed and remaining bits are 6.

§ So 2⁶-2=62

3. identify the value of new subnet mask and the range

§ 255.255.255.11000000

§ 255.255.255.192

§ Range

· 256-192=64

· Maximum possibilities of octet-value of host ID.

4. identify all the valid subnets

§ 192.168.10.0

§ 192.168.10.64

§ 192.168.10.128

§ 192.168.10.192

5. identify all the valid hosts

§ 1-62 hosts

§ 65-126

§ 129-190

§ 193-254

6. identify the broadcast address for each networks

§ 192.168.10.63

§ 192.168.10.127

§ 192.168.10.191

§ 192.168.10.255

IP ADDRESS TROUBLESHOOTING

Statement

We have networks in which there are two routers are R1 & R2. both are connected with huge networks

The address of the serial interface of R1 is 20.1 and R2 is 20.2

The address of the Ethernet interface of R1 is 10.2 and R2 is 30.1

Client of R1 having IP 10.1 and client of R2 is 30.2

Case

Client 10.1 is not able to communicate with server 30.2 of the other networks.

Step to diagnose the problem

1. ping 127.0.0.1 if there is a reply means that TCP/IP stack is o.k. and is not corrupt but if there is no reply means TCP/IP protocol stack is corrupt and you have to reinstall the operating system.

2. if the first step is successfully then try to ping the IP address of PC LAN card if there is a reply means LAN card is O.K. but if there is no reply means LAN card is faulty replace or repair it. We can do repair by right click on the LAN card. It will release the cache memory. Sometime the cache memory is full and card does not work properly.

3. if the first two steps are successfully then try to ping. The IP address of router Ethernet port i.e. default gateway, if there is reply it means there is no problem in the local LAN physical topology. If it does not reply then problem is with cables, hubs or switch part or router Ethernet port. Problem id with physical topology.

4. if the first 3 steps are successfully then try to ping the remote server once again if there is no reply its means problem is with the remote site ask the remote site administrator to follow the above 3 steps to trace the problem.

a. If there is a reply its mean communication takes place it means everything is o.k. and fine.

b. If there is no communication it means problem is with ARP and DNS servers.

IP ADDRESSING

2012-04-15T01:00:00.005-07:00

IP ADDRESSING SCHEMA

In a network every computer having a unique address called IP address which is use to communicate the computer with another computer in the network. Every computer must have IP address. So it very important to understand the concept of IP Addressing Scheme.

An IP address is a 4 octet i.e. 8*4 =32 bits address. Each octet is separated by the dot.

Format of IP address is

0-255.0-255.0-255.0-255

An IP address having two parts. Host ID and Network ID.

192.168.0.1

Here 192.168.0. Is the network ID and 1 is the Host ID

Network ID

This part specifies the unique number assigned to your particular network. It it also the part that identifies the class of network assigned.

Host ID

This is the part of the IP address that you assign to each host, and uniquely identifies each host on your network. Note that for each host on your network, the network part of the address will be the same, but the host part must be different.

IP address having classes

Ø Class A address

Ø Class B address

Ø Class C address

Ø Class D address

Ø Class E address

Class A address scheme

In class A first 8 bits are network address while the remaining 24 bits are host address.

Range of class A is from 0.0.0.0. To 127.255.255.255.

Network address 0 is reserved to designate the default route for the packets and the network address 127 is reserve for the diagnostic to check out the local loop address.

This mean that there are 126 networks are available.

e.g. 86.18.2.4 is a IP of class A with network address 86 and host address is 18.2.4

86.0.0.0. is the network address.

86.255.255.255 is the broadcasting address of a network having network address is 86.

Class B Address Scheme

The first 16 bits are the network ID & remaining 16 bits are the host ID.

The range of the class B address scheme is 128.0.0.0.to 191.255.255.255

142.3.92.19 is an IP that belong to the class B address.

142.3 is the network IP and 92.19 is the Host ID

142.3.0.0. Is the network address

142.3.255.255 is the broadcasting address.

Class C Address Scheme

In the class C 24 bits are the network ID bits and 8 bits are the host ID bits.

The range of the class C address is 192.0.0.0. to 223.255.255.255

192.168.0.10 is the IP of class C. here 192.168.0 is the network ID and 10 is the Host ID

192.168.0.0 is the network address

192.168.0.255 is the broadcasting address.

Class D Address Scheme

The address of this class is used for multicasting. This class does not have any netid and hostid

The IP range for D class address is 224.0.0.0 to 239.255.255.255

Class e address scheme

The address of the E class is reserved for the internet society

The range for the E class is 240.0.0.0 to 255.255.255.255

Point to remember

For class A there is only one private network having netid 10.0.0.

For class B there are 16 private network allowed. Netid for these private networks are from

172.16 to 172.31

For class C there are 256 private network allowed. Netid ranges for these networks are

192.168.0. to 192.168.255

How to convert the decimal IP address to Binary Address?

How to convert 192.168.0.10 to binary number

128 64 32 16 8 4 2 1

Firstly we will convert 192 to binary value. Add the value to make 192 and mark them as 1

128+64=192

So for 192 binary value is 11000000

Other bits are mark as 0

Now 168 =128+32+16+2=10110001

For 0=00000000

For 10 = 8+2=00001010

Now 192.168.0.10 is 11000000.10110001.00000000.00001010

Why we not consider 127 in any range of IP address?

We don’t consider 127 in any IP range because it is reserved as the loop back address. To check the system whether it’s ready for networking or not we use it.

The 127.0.0.1 is known as loop back address. It also allows information technology professionals to test IP software without worrying about broken or corrupted drivers or hardware.

Once you are at a command prompt, enter the following:

Ping 127.0.0.1

If the command is successful, the Ping utility will return results similar to the following. The exact information returned will vary depending on your operating system:

This indicates that the network card and drivers are functioning properly. If the Ping utility is not able to get a return on the network card, this may indicate either a driver problem, or a physical problem with the card.

Private addresses in each class networks

v in class A the private address are

o 10.0.0.0. to 10.255.255.255

v In class B the private address are

o 172.16.0.0. to 172.31.0.0. (16 to 31 networks )

v In class C the private address are

o 192.168.0.0 to 192.168.255.0 (256 networks)

MAC address

Ø MAC address stand for the Media Access Control.

Ø Its 48 bits address

Ø It’s a hexadecimal address

Ø Its known as the hardware or physical address

Ø ARP (Address Resolution Protocol) is used to convert the IP address to MAC address.

POINT TO REMEMBER

Ø When all the host ID portion bits of an IP address are 0, it is a network address.

Ø When all the host ID portion bits of an IP address are 1, then it is a broadcast address.

o 10.255.255.255 ( 10.11111111.11111111.11111111)

Ø When all the net ID portion bits of an IP address are 0, then it is a host address.

o 10.0.0.1 IP address

o 0.0.0.1 host address

Ø When all the net ID bits are 1 it’s represent all the networks.

o 255.0.0.0

Ø When all the net ID bits and host ID bits are 1, its represents global broadcast. Means all networks all hosts.

Ø When all the net ID and host ID bits are 0 , then it is used for default routing

o 0.0.0.0.

Ø 127.0.0.1

o It is loop back address used for self testing. If ping to this address is successful its means the TCP/IP protocol stack is ok. If there is no reply the TCP/IP suite is corrupt it means you have to reinstall the O.S. it does not depends upon the presence of the LAN cards. i.e. if there is no any LAN card present in the computer even then it will reply because it only check the software for the networking ( its means that TCP/ IP suite)

Ø Valid hosts

o Class A 255.0.0.0 2²⁴-2

o Class B 255.255.0.0 2¹⁶-2

o Class C 255.255.255.0 2⁸-2

OSI Seven-Layer Model and DOD

2012-04-15T00:51:00.000-07:00

In the 1980s, the European-dominated International Standards Organization (ISO), began to develop its Open Systems Interconnection (OSI) networking suite. OSI has two major components: an abstract model of networking (the Basic Reference Model, or seven-layer model), and a set of concrete protocols. The standard documents that describe OSI are for sale and not currently available online.
Parts of OSI have influenced Internet protocol development, but none more than the abstract model itself, documented in OSI 7498 and its various addenda. In this model, a networking system is divided into layers. Within each layer, one or more entities implement its functionality. Each entity interacts directly only with the layer immediately beneath it, and provides facilities for use by the layer above it. Protocols enable an entity in one host to interact with a corresponding entity at the same layer in a remote host.

The seven layers of the OSI Basic Reference Model are (from bottom to top):

The Physical Layer :-Physical layer defines and cables, network cards and physical aspects. It defines raw bit stream on the physical media. It also provides the interface between network and network communication devices. It is also responsible for how many volts for 0 and how many for 1. Physical layer also checks the number of bits transmitted per second and two ways or one way transmission. Physical layer also dealing with the optical, mechanical and electrical features.Protocols: Protocols that work on the physical layer are ISDN, IEEE 802 and IEEE 802.2 Network Devices: Hubs, Repeaters, Oscilloscope and Amplifier works on the network devices.
.
The Data Link Layer :-Defines procedures for operating the communication links
Frames packets
Detects and corrects packets transmit errors
Protocols: Logical Link Control
• error correction and flow control
• manages link control and defines SAPs
802.1 OSI Model
802.2 Logical Link Control
Media Access Control
• communicates with the adapter card
• controls the type of media being used:
802.3 CSMA/CD (Ethernet)
802.4 Token Bus (ARCnet)
802.5 Token Ring
802.12 Demand Priority
Network Devices: Bridge
Switch
ISDN Router
Intelligent Hub
NIC
Advanced Cable Tester
The Network Layer:-The network layer determines that how data transmits between the network devices. It also translates the logical address into the physical address e.g computer name into MAC address. It is also responsible for defining the route, managing the network problems and addressing. Router works on the network layer and if a sending device does not break the data into the similar packets as the receiving device then network layer split the data into the smaller units and at the receiving end the network layer reassemble the data.

Network layer routes the packets according to the unique network addresses. Router works as the post office and network layer stamps the letters (data) for the specific destinations. Protocols: These protocols work on the network layer IP, ICMP, ARP, RIP, OSI, IPX and OSPF. Network Devices: Network devices including Router, Brouter, Frame Relay device and ATM switch devices work on the network layer.
The Transport Layer:-Transport layer manages end to end message delivery in a network and also provides the error checking and hence guarantees that no duplication or errors are occurring in the data transfers across the network. Transport layer also provides the acknowledgement of the successful data transmission and retransmits the data if no error free data was transferred.

It also provides and error handling and connectionless oriented data deliver in the network. Protocols: These protocols work on the transport layer TCP, SPX, NETBIOS, ATP and NWLINK.Network Devices: The Brouter, Gateway and Cable tester work on the transport layer.
The Session Layer:-Session layer establish and manages the session between the two users at different ends in a network. Session layer also manages who can transfer the data in a certain amount of time and for how long. The examples of session layers and the interactive logins and file transfer sessions. Session layer reconnect the session if it disconnects. It also reports and logs and upper layer errors.
Protocols: The protocols that work on the session layer are NetBIOS, Mail Slots, Names Pipes, RPC
Network Devices: Gateway
The Presentation Layer:-The presentation layer presents the data into a uniform format and masks the difference of data format between two dissimilar systems. It also translates the data from application to the network format. Presentation layer is also responsible for the protocol conversion, encryption, decryption and data compression. Presentation layer is a best layer for cryptography. Network Devices: Gateway Redirector is operates on the presentation layer.
The Application Layer :-The application layer defines the interfaces for communication and data transfer. This layer also provides and support services such as job transfer, handles network access, e-mail, supports user applications and error recovery.Protocols: FTP, DNS, SNMP, SMTP, FINGER, TELNET, TFTP, BOOTP and SMB protocol are operated on the application layer.Network Devices: Gateway network device is operated on the application layer.

DoD Networking Model

The Department of Defense Four-Layer Model was developed in the 1970s for the DARPA Internetwork Project that eventually grew into the Internet. The core Internet protocols adhere to this model, although the OSI Seven Layer Model is justly preferred for new designs.

The four layers in the DoD model, from bottom to top, are:

The Network Access Layer is responsible for delivering data over the particular hardware media in use. Different protocols are selected from this layer, depending on the type of physical network.
The Internet Layer is responsible for delivering data across a series of different physical networks that interconnect a source and destination machine. Routing protocols are most closely associated with this layer, as is the IP Protocol, the Internet's fundamental protocol.
The Host-to-Host Layer handles connection rendezvous, flow control, retransmission of lost data, and other generic data flow management. The mutually exclusive TCP and UDP protocols are this layer's most important members.
The Process Layer contains protocols that implement user-level functions, such as mail delivery, file transfer and remote login.

BASIC NETWORKING CONCEPTS

2012-04-15T00:36:00.000-07:00

Cisco Certified Network Associate (CCNA®) validates the ability to install, configure, operate, and troubleshoot medium-size route and switched networks, including implementation and verification of connections to remote sites in a WAN. CCNA curriculum includes basic mitigation of security threats, introduction to wireless networking concepts and terminology, and performance-based skills. This new curriculum also includes (but is not limited to) the use of these protocols: IP, Enhanced Interior Gateway Routing Protocol (EIGRP), Serial Line Interface Protocol Frame Relay, Routing Information Protocol Version 2 (RIPv2),VLANs, Ethernet, access control lists (ACLs). (source:-http://www.cisco.com/web/learning/le3/le2/le0/le9/learning_certification_type_home.html).

Cisco Manufacture Devices :

Routers
switches
firewall
IPS(Intrusion Preventions System)
IDS(Intrusion Detection Systems)
Web Filtering
Content Filtering
Antivirus and AntiSpam)
Network Management Hardware and Software )
VOIP Devices
IP Telephony
Wireless Devices. and etc .

NETWORK

When two or more than two computer is interconnected for

Data Communication
Sharing

Data Sharing

i. File , folder and directory sharing

Resource Sharing

i. Printer, plotter, Scanner etc.

NETWORKING

The process, technique, terminology through which a network is being established.

Basic Requirement To Establish Networks

Communication devices

Lan Card

LAN card, NIC card, Ethernet card, Ethernet adapter.

Each LAN card having 48 bit hexadecimal address known as the MAC (Media Access Control Address).

It is the physical address which is preceded within the LAN card and user cannot change it. MAC address of two LAN card cannot be same.

Notes :-In LAN, communication take place through MAC address but in WAN it is through IP address.

Communication Media

There are two types of the media.

Guided media (also known as wired base)

Unguided media (also known as wireless)

Wired based communication

There are three types of guided media as

Coaxial wire

Fiber optics wire

Twisted pair wire

Coaxial wire

This wire is used by the cable operator now.

Core

Core is the data carrier. It cstaarries the data from source to destination.

Thick insulated sheet

Its act as insulation between core and the mesh.
Its provide internal strength to the wire as the whole or core.
Its avoid data leakage.

Copper mesh

It’s used for earthing or ground.
To reduce the EMI (Electromagnetic Interference) effect.

Outershield thin plastic sheet

Its provide external strength to the wire as the whole.
It protect from the weather and climates condition.

Advantage Of The Coaxial Wire

High data transfer rate.
Cheaper
More protection from external interface.

Disadvantage Of The Coaxial Wire

It’s easy to hack.
Regular number of repeater and amplifier are used.
More prone to EMI effect or external interference.

Note :

Electrical signal are used in the coaxial wire and twisted wire but in case of fiber optics the signal are in the form of light or optics.

FIBRE OPTICS

In case of fiber optics the fiber used is made up of glass or silica which is in the sand.

In case of both coaxial and twisted pair data is transmitted in the forms of electrical signal.

But in case of fiber optics the data transfer in the form of light signal or optical signal which is not attenuate easily.

Three components of the optical fiber technology.

light source
Fiber optics

It has 1.5 to 2 km range without any signal lose. The fiber optics works over the principle of the TIR.

TIR stand for the Total Internal Reflection.

Advantage Of The fiber optics Wire

High data transmission rate because the data is transferred with the speed of the light.
Widely coverage 1.5 km to 2 km.
More secure and reliable. Its not to easy to hack.
No chance of any EMI effect or External interference.

Disadvantage Of The fiber optics Wire

Fiber optics is costly.
Difficult to implement specialized knowledge is required to install the fiber optics.
Costly to implement
Lot of legal formalities to install the wire.
Difficult to troubleshoot.

Twisted pair cable

Reason to twist the wires:

Parallel line show antenna which is only a receiver and the transmitter.
The wires are twisted to reduce the EMI (Electromagnetic Interference) effect.

There are eight wires as the four pairs

There are two types of the twisted pairs

UTP (Unshielded Twisted Pair)
STP(Shield Twisted Pair)

In the STP there is a silver foil or mesh on the twisted pair wires. Its means that there is internal shield over the pairs.

UTP	STP
No any shielding is present over the pair	Shielding is present over the pairs
Cheaper	Costly
More chance of EMI	Negligible chance of the EMI
Limited coverage(100-120 m)	Larger coverage (150-200 m)

Types of UTP categories

CAT 3	CAT5	CAT 7
3 twist per inch	5 twist per inch	7 twist per inch
10 Mbps	100 Mbps	1000 Mbps
Cheaper	Cheap	Costly
More chance of EMI	Less chance of EMI	Negligible chance of EMI
Low strength	Good strength	High strength

Types of cable in LAN or Ethernet Cable Types

Straight cable : use to connect different device .
Cross cable : use to connect different device.
Rollover cable : use to connect specific specification.

Straight Cable

The usage of the straight cable

pc to hub or switch
Hub or switch to router.

In the RJ45 jacks only 1,2,3,6 four wire are active others are not actives.

Why we say RJ45 connector.

We say the connector to RJ45 .because 4,5 pin is inactive and after it again 6 pin is active so we say it RJ 45 connector(RJ stand for registered jack).

In case of RJ 11 there are two pin both are active.

Why we use the 8 pin if only 4 pin are active.

We use the 8 pin instead of 4 even there are only 4 pin are active this is only a future planning. As reliance announces that they will provide such environment in which only from one wire you can get the telephone service, television services and internet.

Telephone two wire require as one for receiving other for transmitting

In case of television two wires require as one for transmitting and other earthing.

In case of internet service four pin are required as two for transmitting and two for receiving.

Coding for the straight wire

Here orange and green are active color and they are on the active pin as 1,2,3,6. So we take blue color in the 3 and 6 as 45 numbers. Here blue and brown color having no any importance.

Cross Cable

Usage

This is used to connect the similar devices as

1. Pc to Pc

2. Hub to Hub

3. Switch to Switch

4. Hub to Switch

5. Modem to Pc

6. Pc to router

Rollover cable

In the case of the rollover cable the whole wire is changed. We count the number by seeing the metal head not the jack head.

The rollover wire is also called console cable. This is used to get the access of the router from the pc in order to configure it. If we make it as shown above scheme then both end are RJ45 connector but we must have a serial or com port to get the access of router for configuration so we use a connector which change the RJ45 interface to serial interface.

How to check the wire?

To check the cross wire or straight wire

Put one end in the RJ45 jack of hub and other end in the jack. If both the light is on then its mean that your wire is ok otherwise there is some problem with wire.

To check the straight wire

Put one end in the RJ45 jack of hub and other end in the upload jack. If the light is on then its mean that the wire is ok.

Wireless Media

There is different type of the wireless media as

Radio Connectivity
Microwave Connectivity
Infra-Red Technology

Radio Connectivity

In this case radio connectivity data is transmitted in the form of radio waves.

Characteristics

Radio wave are omni directional (multidirectional) i.e. They can travel in all the direction
Radio wave can easily bypass the physical objects.
Radio waves are frequency dependent.

Disadvantages

Limited coverage i.e.(45 km to 50 km)
Limited bandwidth i.e. Data transfer rate is limited
Unsecured and unreliable
May get affected due to whether and climatic conditions.

Examples

a) Radio sets

b) Wireless sets

c) Walky talky

Microwave technology

In this technology data is transmitted in the form of microwaves.

Characteristics

Microwaves are unidirectional i.e. they can travel in only one direction.
Point to point connection
Microwaves can’t bypass the physical objects
Wider coverage i.e. World wide
High data transfer rate i.e. Bandwidth
Not easy to hack thus these are more secure and reliable.

Disadvantages

1. costly

2. May get affected due to bad weather and climatic condition.

3. Cannot bypass the physical objects.

Examples

a) Mobile phones

b) Cable television

c) VSAT

d) ATM

INFRARED TECHNOLOGY

Data is transmitted in the form of infrared rays.

Characteristics

1. Infrared rays are unidirectional

2. Its cannot bypass the physical objects.

3. Coverage is limited

4. Slow data transfer rate

5. Easy to hacks.

Examples

a) Remote control

b) Infrared in mobiles etc.

NETWORKING DEVICES

There are three main devices used in the networking.

1. Hub

2. Switch/Bridge

3. Router

HUB

a) It is a networking device that is used to connect two or more than two computer within a network.

b) It is a duffer device because it does not know any type of address i.e. Neither MAC nor IP addresses.

c) Its only knows the source port so when it broadcast the data then it will broadcast data all the port except the source port.

d) It’s internally based on bus topology according to which only one user can communicate at a time. Either he can send the data or receive the data

e) It divides the actual bandwidth among the users.

f) Hub always makes a broadcast and as a result of broadcast bandwidth will get wasted.

g) Collisions are common in case of Hubs. Due to collision data loss as well as wastage of LAN bandwidth.

h) Its based on the CSMA/CD technology (Carrier Sends Multi Access/collision detection)

i) Broadcast domain

a. Area or LAN affected by the broadcasting.

b. Broadcast domain one

j) Collision domain

a. Area or lines affected by the single collision

b. Collision domain one

SWITCH

a) It is a networking device that is used to connect two or more computers within a LAN.

b) It is an intelligent device because it works on MAC addresses.

c) Its internally based upon the star topology. So all the user can communicates at the same time with same bandwidth.

d) It provides additional bandwidth to the existing users in comparison to your hubs.

e) MAC table is also known as filter table or CAM table.

f) When a source send a message for the destination. First of all there is a Mac address table. There must be entry of source and destination. If there is no any entry of the source then it will be there. After it, it will check whether there is an entry for the destination. If it is not present there then it will broadcasting. Once the address is there in the table then it has no need of broadcasting. But when we start the switch then always first of all it makes broadcast to enter the entry for the client computer once it fill up then there is no any type of broadcasting. Ie. Limited broadcasting.

g) No collisions are here in case of a switch.

h) Broadcast domain= one

i) Collision domain =no. of ports of a switch.

Switch	Bridge
1. Switch is a hardware based device because ASIC(Application Specific Integrated Circuits) are used to create and maintain the MAC address table	It is software based device because software is used to create and maintain MAC table.
Switch is a multiport bridge	The maximum numbers of ports in case of a bridge can be 16.

Similarities

1. Both are layer two devices. i.e. Data link layer

2. Both works on MAC address.

ROUTERS

1. It is a networking device that is used to connect two or more than two different networks.

2. It is an intelligent device that works on IP addresses.

3. Routing mean to identify the route to reach from source to destination.

4. Packet filtration is done to restrict any unauthorized access or any unauthorized material form entering into your network from outside environment.

5. No broadcasting

6. No collision

7. Broadcast domain = no. of ports

8. Collision domain = no. of ports of router.

Thanks.......

How to Secure Your Wireless Network Connection

2012-04-14T11:54:00.000-07:00

As we seen today majority of people don't bother about there wireless connections ,it is a serious MISTAKE . Suppose we got a hacker around, do you have any idea what he can do to you... he is able to get your credentials like bank account,mail accounts or any valuable project details that your stored in your laptop... Look how terrible it would be then....

ahh.... well i got few tips to secure your wireless connection:)

Before moving on to it let me tell you how good and bad a wireless connection could be.

Wireless networks are GOOD because they help eliminate the physical constraints which we have with our weired networks.
Wireless networks are BAD because they create an additional security risk by sending data through the air.

Let me know you some network standards....

802.11a - 54 Mbps, short range,very expensive (Not used in these days)
802.11b - 11 Mbps, Good range,slow (Not used in these days)
802.11g - 54 Mbps, Good range, fast
802.11n - Over 100 Mbps, Very fast

Wireless Security may established by implementing the following .....

Note:- Different routers have different interface.

Step 1. Open your router settings page

First, you need to know how to access your wireless router’s settings. Usually you can do this by typing in “192.168.1.1” into your web browser, and then enter the correct user name and password for the router. This is different for each router, so first check your router’s user manual.
You can also use Google to find the manuals for most routers online in case you lost the printed manual that came with your router purchase. For your reference, here are direct links to the manufacturer’s site of some popular router brands – Linksys, Cisco, Netgear, Apple AirPort, SMC, D-Link, Buffalo, TP-LINK, 3Com, Belkin,

Linksys equipment can be accessed by using admin for both username and password fields.

Step 2. Create a unique password on your router

Once you have logged into your router, the first thing you should do to secure your network is to change the default password* of the router to something more secure.
This will prevent others from accessing the router and you can easily maintain the security settings that you want. You can change the password from the Administration settings on your router’s settings page. The default values are generally admin / password.

Its not all safe to use default user name and password you must change it to more secure one.

Step 3. Change your Network’s SSID name

The SSID (or Wireless Network Name) of your Wireless Router is usually pre-defined as “default” or is set as the brand name of the router (e.g., linksys). Although this will not make your network inherently* more secure, changing the SSID name of your network is a good idea as it will make it more obvious for others to know which network they are connecting to.
This setting is usually under the basic wireless settings in your router’s settings page. Once this is set, you will always be sure that you are connecting to the correct Wireless network even if there are multiple wireless networks in your area. Don’t use your name, home address or other personal information in the SSID name.

NOTE:- Always set ssid name like "c:/virus.exe" ,"police-department" to get hackers away:"

Step 4. Enable Network Encryption

In order to prevent other computers in the area from using your internet connection, you need to encrypt your wireless signals.
There are several encryption methods for wireless settings, including WEP, WPA (WPA-Personal), and WPA2 (Wi-Fi Protected Access version 2). WEP is basic encryption and therefore least secure (i.e., it can be easily cracked*, but is compatible with a wide range of devices including older hardware, whereas WPA2 is the most secure but is only compatible with hardware manufactured since 2006.
To enable encryption on your Wireless network, open the wireless security settings on your router’s configuration page. This will usually let you select which security method you wish to choose; if you have older devices, choose WEP, otherwise go with WPA2. Enter a passphrase to access the network; make sure to set this to something that would be difficult for others to guess, and consider using a combination of letters, numbers, and special characters in the passphrase.

[*] What do the bad guys use - AirCrack and coWPAtty are some free tools that allow even non-hackers to crack the WEP / WPA (PSK) keys using dictionary or brute force techniques. A video on YouTube suggests that AirCrack may be easily used to break WiFi encryption using a jail-broken iPhone or an iPod Touch.

Step 5. Filter MAC addresses

Whether you have a laptop or a Wi-Fi enabled mobile phone, all your wireless devices have a unique MAC address (this has nothing to do with an Apple Mac) just like every computer connected to the Internet has a unique IP address. For an added layer of protection, you can add the MAC addresses of all your devices to your wireless router’s settings so that only the specified devices can connect to your Wi-Fi network.
MAC addresses are hard-coded into your networking equipment, so one address will only let that one device on the network. It is, unfortunately, possible to spoof a MAC address*, but an attacker must first know one of the MAC addresses of the computers that are connected to your Wireless network before he can attempt spoofing.
To enable MAC address filtering, first make a list of all your hardware devices that you want to connect to your wireless network**. Find their MAC addresses, and then add them to the MAC address filtering in your router’s administrative settings. You can find the MAC address for your computers by opening Command Prompt and typing in “ipconfig /all”, which will show your MAC address beside the name “Physical Address”. You can find the MAC addresses of Wireless mobile phones and other portable devices under their network settings, though this will vary for each device.

[*] What do the bad guys use - Someone can change the MAC address of his or her own computer and can easily connect to your network since your network allows connection from devices that have that particular MAC address. Anyone can determine the MAC address of your device wireless using a sniffing tool like Nmap and he can then change the MAC address of his own computer using another free tool like MAC Shift.

Step 6. Reduce the Range of the Wireless Signal

If your wireless router has a high range but you are staying in a small studio apartment, you can consider decreasing the signal range by either changing the mode of your router to 802.11g (instead of 802.11n or 802.11b) or use a different wireless channel.
You can also try placing the router under the bed, inside a shoe box or wrap a foil around the router antennas so that you can somewhat restrict the direction of signals.
Apply the Anti-Wi-Fi Paint – Researchers have developed a special Wi-Fi blocking paint that can help you stop neighbors from accessing your home network without you having to set up encryption at the router level. The paint contains chemicals that blocks radio signals by absorbing them. “By coating an entire room, Wi-Fi signals can’t get in and, crucially, can’t get out.”

Step 7. Upgrade your Router’s firmware

You should check the manufacturer’s site occasionally to make sure that your router is running the latest firmware. You can find the existing firmware version of your router using from the router’s dashboard at 192.168.*.

Connect to your Secure Wireless Network

To conclude, MAC Address filtering with WPA2 (AES) encryption (and a really complex passphrase) is probably the best way to secure your wireless network.
Once you have enabled the various security settings in your wireless router, you need to add the new settings to your computers and other wireless devices so that they all can connect to the Wi-Fi network. You can select to have your computer automatically connect to this network, so you won’t have to enter the SSID, passphrase and other information every time you connect to the Internet.

Your wireless network will now be a lot more secure and intruders may have a tough time intercepting your Wi-Fi signals.

How to make windows 7... blazing fast !!

2012-04-14T06:49:00.000-07:00

Windows 7 is Engineered for speed. Special attention has been given by the Windows 7 team for making Windows 7 faster than the previous operating systems. Windows 7 is much faster than Windows Vista, but even then most of us don’t get satisfied with it. There are many who still have their old PC. Installing Windows 7 on them wont be as soothing as they work with XP and Even with latest hardware’s installed some users are still avaricious for more performance. Though we don’t make it lightning fast, we can optimize Windows 7 to the maximum possible extent and enjoy the maximum performance we could squeeze out from it. So for all the extra performance lovers, let me present you with this Ultimate Guide To Speed Up Windows 7.

I guarantee that after following this guide and implementing the recommendations on your PC, you will really get some performance gain.

The bare Minimum Requirements You need To Run Windows 7

1) 1GHz processor (32- or 64-bit)

2) 1GB of main memory

3) 16GB of available disk space

4) Support for DX9 graphics with 128MB of memory (for the Aero interface)

5) A DVD – R/W drive

Even if you don’t have the DX 9 graphics card there is no problem because our target is performance and not the ” Eyecandy ” . Of course if you need the aero experience you need a powerful graphics card for sure.

So lets start The Ultimate Guide to Speed up Windows 7

Disabling the Search Indexing Feature in Windows 7
1. Right Click the “Computer” Icon in the desktop and select “Manage”.
2. Click “Services and Applications” in the “Computer Management” window.
3. Click on “Services”.
4. You can see a lot of services listed there. Look for “Windows Search”.
5. Right Click on “Windows Search” from the list and choose “Properties”.
6. The “Windows Search Properties Window” will open up. From “Startup type” click on the drop down menu and choose “Disabled”.
7. Click “Apply” then “OK” and that’s it. The Windows 7 Search Indexing Feature is now disabled.

Most of the Windows 7 users do less searches in there system. The Search Indexing service in Windows 7 will index keeps track of the files so that they can be found quickly when asked at some other time. This feature is useful only if you perform frequent searches on your system.

For occasional file searchers the Search Indexing service in Windows 7 is a total resource hog. It unknowingly eats up your system resources. What you need from windows 7 is maximum performance from it then i would certainly recommend you to disable this resource hogging Windows 7 Search Indexing Feature.

To Disable the Search Indexing Feature in Windows 7

If you want to completely disable the search indexing feature in Windows 7 you can set the Search Indexing Service to Manual (See the above method about disabling unwanted services).

Disable the Aero Theme on Windows 7
- Right Click on your Desktop and select ” Personalize ” click the Window Color Tab.
- Uncheck the Box saying ” Enable Transparency ” and then click on ” Open classic appearance properties for more color options”.
- Then a window will open up. Apply a Standard or Basic theme from it. The Standard Windows 7 theme is more preferred.

The aero user interface certainly adds some ” Eyecandy ” to Windows 7 but certainly is a resource hog especially when, what you expect from windows 7 is more performance juice. Aero user interface squeezes your graphics or video card to its maximum. So why dont we just avoid the Windows 7 aero? if we care more about speed and performance in Windows 7. So Disabling the Aero in Windows 7 certainly adds an extra speed boost to it.

Disabling the aero theme alone in Windows 7 will really speed things up. You can know this by looking into the memory consumption when aero is turned on and off.

Disabling the Unwanted Visual Effects in Windows 7 to Speed Up more
1. For this right click on ” Computer” and select “Properties” from the right click menu.
2. Click on ” Advanced System Settings ” from the left pane to open up the ” System Properties ” window.
3. Select the “Advanced” tab from it. Then Under ” Performance ” click ” Settings “. Choose ” Custom: ” Options From it.
4. Now un tick all the options and select only the last four options (actually three only needed; you can un tick the second option from the last four). See the screen shot if you have any doubt.
5. Now just logoff your system and turn logon.

Even though we have tuned off the aero effects in Windows 7 still there are many unwanted visual effects that can be safely disabled to speed up windows 7 even more.

You will now notice the speed difference now.

Using minimal Sound Effects

For disabling sound effects, do the following:

Click Start. In the search box type mmsys.cpl and press Enter
In the Sound window (refer figure) that appears click on Sounds tab
Set the Sounds scheme to ‘No Sounds‘
You could set only the essential sounds if needed in the Program Events, by selecting the specific event and then choosing the sound from the Sounds drop-down menu below.
You can as well disable the "Play Windows Startup sound" option.
After the settings are done, click Apply and OK.

Disable or make unneeded services Manual

Some processes and services, which might not really be necessary, are by default made to start automatically once the system starts up. They will consume RAM as well as the processor’s attention, slowing down other important tasks. It is best to disable them. For this, do the following:

Click Start. In the search box type services.msc and press Enter
Go to Services & Applications > Services. You’ll see the Services window (refer figure).
Right-click on a service that you wish to set to manual or disable. If the service is already started, Stop it first.
Once the service is stopped, again right-click on it and select Properties.
In the Startup type, you can either set the service to Manual, if you would be using it later, or Disable it, if not needed.
Once done, you can close the window.

Disabling the Unwanted Start-up Services/Programs to Speed up Windows 7

Some programs are set to start during system start-up. These might slow down the start-up process. Programs that are not really needed during start-up can be disabled. For this, do the following:

Click Start. In the search box type msconfig and press Enter.
In the System Configuration window (refer figure), go to Startup.
Uncheck the box next to those processes that are not important for start-up. This will disable them.
Once you’ve disabled the processes, click Apply and OK.

Disable the User account control (UAC) Feature in Windows 7
1. From the Control Panel open the ” User Accounts and Family Safety ” > User Account.
2. Click the User Account Control settings link.
3. Now just Drag the Slider towards “Never Notify”.
4. Click “OK” and Reboot your system.

The User account control (UAC) feature in Windows 7 is very annoying though it says it can protect your computer from harmful virus activity etc. But if you are a daily user of your computer this windows 7 feature will be a total nuisance to you.

To Disable and Turnoff UAC in Windows 7

Disabling UAC is for advanced users only its not recommend doing it if not.

SetUp the Windows 7 Ready Boost Service for an Extra Speed Boost
1. To configure the Ready Boost Feature in Windows 7 you need to have a High Speed Flash/USB or Pendrive with you which is ready boost compatible.
2. After plugging you pendrive, open “Computer” > Right-click the on USB Drive/Pendrive > select “Ready Boost” tab > tick the “Use this device” checkbox.
3. You can configure how much space on your USB drive/ Pendrive to be used as Ram.

The ready boost feature in Windows 7 will help you to use your flash drive or pendrive or USB drive as Ram there by improving the performance and speed of windows 7 greatly. You can certainly experience it when launching bulky applications such as Adobe Photoshop etc.

Turn off Unused Windows 7 Features
1. Open up ” Programs and Features ” from Control Panel.
2. Click the ” Turn Windows features on or off ” from the left pane.
3. Now uncheck all the Feature that you don’t use in Windows 7 and restart the system for the changes to take effect.

There are many feature in windows 7 that we often don't use. Disabling these unused features in Windows 7 will really help in speeding things up.

Disable the Windows 7 Sidebar (Actually the Gadgets)
1. Right click on the sidebar and select ” Properties “.
2. On the properties windows untick the check box showing ” Start sidebar when Windows Starts “
3. From now on windows sidebar won’t start when windows 7 start up.

Disabling the window 7 sidebar is definitely help you to to gain a few seconds during start up time. There are many useful utilities such as the RocketDock etc. which are good application launchers.

To Disable the Sidebar in Windows 7.

Change the Power Plan To Maximum Performance
1. Double click the ” Power Options ” in the Control panel.
2. Click the down arrow showing ” Show Additional Plans ” to see the ” High Performance ” power plan
3. Now just activate the ” High Performance ” plan and that’s it.
4. You may go for the advanced settings for further tweaking if you want.

The Power settings in Windows 7 is not automatically set for maximum performance. By default the power plan in Windows 7 is set for a balanced performance with energy consumption on hardware. So you may not get the optimal performance from windows 7 if this is the case. So we need to change the power plan to High Performance Mode.

Disable the Thumbnail Preview Feature to speed up File browsing in Windows 7
1. Double Click on ” Computer ” >click on the “Organize” drop-down menu and select the “Folder and Search options”
2. Under ‘Files and Folders’ section, go to the “View” tab and tick the check box showing “Always show icons, never thumbnails” checkbox.

The thumbnail preview feature in Windows 7 will show the small thumbnails of the contents of a folder instead of showing it’s icon. But this feature really do take up some system resources. So by disabling the Thumbnail Preview feature in Windows 7 the file browsing in Windows 7 explorer can be speed up.

For disabling thumbnails in Windows 7.

Most Essential Softwares To Speed Up Windows 7

In order to maintain your Windows 7 Performance and keep it up in Top Shape there are some very essential software’s that can help us to Speed Windows 7. I will list some of them here. You can download these utilities. But i remind you that you need to run these utilities at least once in a week. Only if you do it regularly your Windows 7 will be in top shape every day.

Turn OFF Windows 7 Screen Saver and Wallpaper
- Right click on desktop and choose “Personalize”.
- Click the Screen Saver link ” From the Screen Saver drop down menu, Set it to “None” and click “Apply” and then “OK”.
- Now click on “Desktop Background” link.
- From the “Location” drop down menu select “Solid Colors” and pick one color and click “OK”.

In order to display the wallpaper and screen saver the system needs some memory. So by disabling those two we can save a few Mega Bytes of memory.

To Disable The Screen Saver and Wallpaper in Windows 7,

Run a trusted Anti-Virus program

Ensure that you have a good anti-virus software loaded on your laptop/computer. This will ensure that no malware or spyware gets planted in your system. Without such protection software, there are chances of third party malware and virus being installed or stored on your system, causing harmful effects and also eating up precious space.

Install only essential software

Ensure that you install only that software which you need. If you install any trial software and find out that you don’t really need it, uninstall and delete it immediately. Else, they might hog precious disk space, RAM and processor cycles. If you’ve installed a software, which you are unable to get rid of, and which is hampering the normal functioning of your laptop, then you might have to format your hard drive. Be aware that formatting your hard drive might wipe out all your data. Therefore it is best you take a back-up before going ahead with formatting.

Clean up the hard drive

Remove unwanted files, like temp files, downloaded program files, recycle bin, etc. You could use Disk Cleanup option to do this, as follows:

Click Start > All Programs > Accessories > System Tools > Disk Cleanup
The system will first calculate how much space can be freed up this way. In the Disk Cleanup window (refer figure) that appears, select the files in that need to be deleted under the Files to delete list.
For deleting ‘System Restore‘ and ‘Shadow copy‘ files, click "Clean up system files" and then on "More Options" tab
Finally click OK. You’ll be prompted again before the deletion. Click Yes.

Enable Write caching on device

This is an option which allows the OS to flush changed data to the hard disk when the system is idle, so that performance is not affected when in use. For enabling this, do the following:

Press Windows key and while holding it down, press Pause/Break key.
In the window that appears, click on Device Manager in the left hand pane.
In the next window that appears, expand Disk drives.
The drop-down list will show the hard drive. Right-click on it and select Properties.
Click the Policies tab in the Device Properties window (refer figure).
Check the box next to "Enable write caching on the device"
You can as well check the box next to "Turn off Windows write-cache buffer flushing on the device" and then click OK.

Note: However, there is one disadvantage in enabling these options – if there is a power outage or a system crash, data might be lost or corrupted. If you have a secondary power supply, like a UPS, you could go ahead with checking these options.

Perform Disk De-fragmentation

When there is no sufficient space to store in a hard drive, the OS splits the file into parts and stores it in different areas on the hard drive. Defragmenting allows all these parts to be stored in contiguous memory locations. For defragmenting disk do the following:

Click Start > All Programs > Accessories > System Tools > Disk Defragmenter
In the window (refer figure) that appears, click on the drive that you want to defragment and then click Analyze disk.
This will estimate the time required for the process. When done click on Defragment disk.
Once done you can either View Report or click Close.

That's pretty much sum up the small things that you can do, to make a big difference to your Windows 7′s performance. If you have some personal tips you’ve done yourself to improve the performances, I’d like to hear from you.

New Generation IT

Understanding of Basic Windows Services

Improve performance by disabling Windows 7 services

Disabling services

TWEAKING SERVICES WITH MSCONFIG?

Disabling services to recover system resources

Other services

Learn How to speed up your system's Boot up time

Top 10 Ways to Speed Up Your Computer’s Boot Time

10. Tweak Your BIOS

9. Clean Out Programs that Launch at Startup

8. Delay Windows Services That Run at Startup

7. Change Your Boot Menu's Timeout Values

6. Disable Unused Hardware

5. Keep Your Antivirus Running and Up to Date

4. Remove Unnecessary Fonts

3. Upgrade Your RAM

2. Give Your Computer a Static IP

1. Install a Solid State Drive

There is a way to look out boot Time

Keyboard Tricks in Windows 7

Troubleshooting Root Login Problems In Linux

Root Login Problems

Installing Redhat Enterprises Linux ,kickstart

yum and Fdisk,Increasing the Size of Swap Partition In Linux

rpm,Task Automation and Scheduling In Linux

Aliases,default permission,runlevel,welcome message at time of login In Linux

Redirecting Input /Output,Symbolic links,Checking Free Space In Linux

Hard Link and Soft Link in Linux

What is the difference between Hard Link and Soft Link in Linux?

User And Group Managemen in Linux

Use of text Editors in Linux

Linux file system Simplified

Getting help,File and Directory Permissions In Linux

Understanding Basic Linux Commands

Some Interesting Facts On LINUX

Introduction To LINUX

Important Port Numbers You Should Know

SUBNETTING AND IP ADDRESS TROUBLESHOOTING

IP ADDRESSING

OSI Seven-Layer Model and DOD

DoD Networking Model

The Department of Defense Four-Layer Model was developed in the 1970s for the DARPA Internetwork Project that eventually grew into the Internet. The core Internet protocols adhere to this model, although the OSI Seven Layer Model is justly preferred for new designs.

BASIC NETWORKING CONCEPTS

Communication devices

Lan Card

Wired based communication

Coaxial wire

Core

Thick insulated sheet

Copper mesh

Outershield thin plastic sheet

FIBRE OPTICS

Twisted pair cable

How to Secure Your Wireless Network Connection

Wireless Security may established by implementing the following .....

Step 1. Open your router settings page

Step 2. Create a unique password on your router

Step 3. Change your Network’s SSID name

Step 4. Enable Network Encryption

Step 5. Filter MAC addresses

Step 6. Reduce the Range of the Wireless Signal

Step 7. Upgrade your Router’s firmware

Connect to your Secure Wireless Network

How to make windows 7... blazing fast !!

Disabling the Search Indexing Feature in Windows 7

Disable the Aero Theme on Windows 7

Disabling the Unwanted Visual Effects in Windows 7 to Speed Up more

Using minimal Sound Effects

Disable or make unneeded services Manual

Disabling the Unwanted Start-up Services/Programs to Speed up Windows 7

Disable the User account control (UAC) Feature in Windows 7

SetUp the Windows 7 Ready Boost Service for an Extra Speed Boost

Turn off Unused Windows 7 Features

Disable the Windows 7 Sidebar (Actually the Gadgets)

Change the Power Plan To Maximum Performance

Disable the Thumbnail Preview Feature to speed up File browsing in Windows 7

Most Essential Softwares To Speed Up Windows 7

Turn OFF Windows 7 Screen Saver and Wallpaper

Run a trusted Anti-Virus program