Creating a Dial-Up Connection

In this age of broadband and wi-fi I know it is only those unlucky guys go for a dial-up one. Anyway Linux is meant for all and with that simple note let me begin, first explaining what is a dial-up connection. A dial-up connection requires your computer's modem to dial a phone number that connects to your Internet Service Provider (ISP). Your computer may have a modem built in, or you may have to use a modem card if your system is a laptop.

To create a new modem connection in a Red-Hat system:

1. From the Applications (the main menu on the panel) menu, choose System Tools => Internet Configuration Wizard.

2. A window opens requesting your root password. Enter it and click OK.

3. The Add new Device Type window opens.

4. The left pane lists each of the possible connections. Choose Modem connection and click the Forward button.

5. Red Hat Enterprise Linux probes for a working modem installed on your computer. If it does not find one, make sure that you have a hardware modem, and that it is installed correctly.

6. The next screen contains three drop-down boxes.

o Modem Device — This menu lists all modems installed on your system. Select the correct modem for this connection.

o Baud Rate — Select the speed of your modem. This list is in bytes: a 56.6K modem is listed as 56700.

o Flow Control — Select Hardware if your modem is a hardware device installed on your system.

When finished making your selections, click the Forward button.

7. The next screen requires information about your ISP. For users in the United States, type the correct information in each field:

o Prefix — Enter any prefix necessary to reach your access number. This might be "1" if the call is long distance, or "9" to reach an outside line.

o Area Code — Enter the area code of your access number, if necessary.

o Phone Number — Enter the access number for your ISP. Do not enter "dashes" in the number.

o Provider Name — Enter the name of your ISP.

o Login Name — Enter the login your ISP has given you.

o Password — Enter the password for your account.

Finally, click the Forward button.

8. On the next screen, select whether your system must automatically obtain your IP address settings or whether your system must use the same IP address every time you connect. To use the same address every time, enter the address your ISP gave you into the Manual IP Address Settings fields. Click the Forward button to continue.

9. The final screen is a summary of the values you have entered. Review them to be sure that all settings are correct. Click the Apply button to create your new connection.

10. The Network Configuration screen appears, showing your new connection along with a list of all other connections on your machine.

11. Test your new connection by clicking the Activate button. If your connection works, go to File => Save from the Network Configuration main toolbar, then exit the application. If your connection does not work, click the Edit button to change the settings.

To access your connection later, select Applications (the main menu on the panel) => System Settings => Network. The Network Configuration window opens. Select the appropriate connection and click Activate.

WAT TO DO WHEN XWINDOW FREEZES

If your Xwindow freezes sometimes, here are two ways that you may try to kill your system. The first is the simple simple way of killing your X server the key combination: Ctrl+Alt+Backspace

The second way is a little more complicated, but it works most of the time. Hit Ctrl+Alt+F2 to startup a virtual console, then log in with your user name and password and run:

# ps -ax | grep startx

This will give you the PID of your Xserver. Then just kill it with:

# kill -9 PID_Number

To go back to your first console, just hit Alt-F1

BASIC LINUX COMMANDS

The following are the basic Linux commands, and are listed with their uses.

1) ls -: list the contents of the current directory. Only files that are not hidden are listed.

2) ls –la -: list the hidden files too, with sole permissions displayed

3) cd :- chage directory to the specified one . (eg: cd /tmp , where tmp is the specified directory)

4) cd.. :- change to the parent directory

5) pwd :- list the present working directory

6) ps –e :- list all the currently running processes with process numbers

7) kill :- kill a process ( eg : kill 4709 where 4709 is the process no)

8) mkdir :- make a new folder. ( eg: mkdir /new )

9) su :- if you are a regular user, typing su , then root password will give you permissions of root user.

10) df –h :- list the current usage status of all drives associated with your Linux system and the available free spaces.

How to mount other file systems

Right click on the desktop if you are using GNOME desktop. Then open Terminal

1) type "su" , followed by the root password
2) type "fdisk -l"
3) find out the partition to be mounted ( say viz. /dev/hda10 )
4) type " mount -t 'filesystem type' 'partition name' 'mount point'


filesystem type - if u r using fat 32 file system, it will be "vfat". ntfs will not be supported by default.

mount point= its where u need to associate your windows partition (drive) into linux. you can create several mount points ( simply FOLDERS) . for eg, if u want to create one do it as,
/mnt/win , where /mnt would be present by default and you are just making a folder named win where u can put all ur data in

SQUID tweaks

I assume you have already set up a Squid proxy and a firewall and that both work correctly. You may now wish to force all your users to use the Squid proxy for surfing the WWW. This is what "transparent proxying" is about: your users surf, even without having defined a proxy in their browser settings, but they in fact all use the transparent proxy and don't notice it.

To enable transparent proxying with Squid, insert the following lines in the configuration file (squid.conf, usually in /etc) at the aproppriate place (search the configuration file for the respective keywords, httpd_accel_host, httpd_accel_with_proxy and httpd_accel_uses_host_header):

httpd_accel_host virtual
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

You will also need to accept and redirect the WWW traffic to port 3128 of the Squid proxy:

ipchains -A input -p TCP -d 127.0.0.1/32 www -j ACCEPT
ipchains -A input -p TCP -d 192.168.0.0/32 www -j ACCEPT
ipchains -A input -p TCP -d any/0 www -j REDIRECT 3128

or, if you use SuSEfirewall2

FW_REDIRECT_TCP="192.168.0.0/24,0/0,tcp,80,3128"

Restart Squid and the firewall. Transparent proxying should be working now. However there are some issues associated with the above settings. You can read about them in the corresponding comments in the squid.conf file.

how to install softwares when source code is available

you may have noticed that some softwares are coming as source codes, ie a bundle of '.c' files .Most of them will be in zipped form( .tar.gz) , so you need to right click & extract to some directory. To install these into your system, i recommend the following way.


1) most softwares will have a backend called ' library 'and a front end called ( the name itself or ui ..etc) .Unzip these into the folder.

2) if library is present , use ' cd ' comand to enter the directory . there after you need to enter three commands to install that package.

a) ./configure
b) make
c) make install

3) do this for both

HOW TO RECOVER ROOT PASSWORD

1) restart ur pc . When bootloader appears, highlight Redhat Linux using up/down arrows and then hold down "e" .,if the bootloader is not password protected. ,otherwise press 'p' and enter your password.
you will be in single user mode.
2) now u will see three lines, go to the second line press 'e' again and at the last of this line write either "s" or "1" or "single" then press enter then press 'b' to boot.
3) now u will be in single user mode and will lead you to a prompt like this " sh# "
4) now enter the command "passwd" to change the password.