Help File Library: Debian: Internet Connection
Introduction
Ok, we've all been there. At least I for one will admit I have. You get
your first Linux installation the way you want it, and then you want to
get access to the internet, get your e-mails etc, yet you're not really
sure to go about it. The purpose of this document is to give you the
information you will need to setup a PPP connection to your ISP in Debian.
I based this article on version 2.1 and as much, some earlier releases
may not conform to that which is mentioned.
If anyone has any feedback on this document, then please mail me
Note: At this time, the procedures outlined here do not cover the
following related, and in many cases essential, topics. However, these
are mentioned, and directions to information have been given where
possbile.
- Kernel Configuration for PPP support
- Modem configuration
Preparation
Believe it or not, this part is often the hardest, but also the most
rewarding.
Information
If you have read the pre-installation Help File, you will have noted the information specific to your account
with your ISP. If not, the information you will need is listed below.
- ISP account username:
- ISP Account password:
- Phone number:
- authentication type: eg PAP, CHAP, none Contact your ISP if
unsure
- DNS Servers:
- POP server:
- SMTP server:
- news server:
- ISP proxy server: if applicable
Commands and Environment
You may also want to read a little about how Linux works, what commands
perform what functions, etc. For a more complete references list, see the bottom
of this document.
Your Kernel
You hopefully compiled PPP support (PPP is a connection oriented service
which you will use to conncet to your ISP) into your kernel when
installing. To check, you can type
dmesg | less
to obtain your bootup messages. Scrolling through this list, if you see
lines beginning with PPP then you have support compiled into your
kernel.
If not, you need to recompile your kernel for PPP support. This is not
covered here, but links to information that will help you have been
included at the end of the document.
Your Modem
You need to establish the type of modem you have in relation to how/where
Linux will use it. If your modem is an external one, the chances are it
will be located on a Serial (ttySX) port, where X is a number. ttyS0 =
COM1 in dos, ttyS1 = COM2. This document does not cover setting up your
modem. There are many obstacles in this field, and many varied ways to
achieve this.
You need to make sure you do not have a winmodem (a device that can only
be used as a modem by Microsoft OSes, and is not technically a modem at
all), as this will stop you from connecting to the world until you get a
new modem. You can establish as to whether the modem is a winmodem by
consulting the manufacturers, or reading the doumentation mentioned at the
end of the documentation. Although this is not strictly true, people in
the past have advocated the rule "If its an external modem, its not a
winmodem". In reality, if your modem is an external one, your chances
are slim of it being a winmodem.
Internal Modems can also provide different obstacles depending on whether
they are ISA or PCI.
Configuration
There are a number of ways to configure your system, but I am hopefully
going to take you throught the quickest way of getting to the outside
world. Other methods of configuration are left to you to find out...
learning is fun!
Security
Whole books have been written on this, but a straightforward method of
security for the purpose of testing your PPP conenction can be achieved
through editing the following files.
- /etc/hosts.deny
Open this file with your favorite text editor (Vi is the authors prefered
choce)and ensure this line is contained in that file
ALL: ALL
- /etc/hosts.allow
Again, open this file as you did /etc/hosts.deny,
and add the following
ALL: LOCAL
pppconfig
This is where it all starts happening. Get the documentation
you collected together earlier for this. The following
is given as one step for each screen in the pppconfig
utility. This utility will setup everything else you
need for your PPP conection.
Make sure you are logged in as root beofre following these steps:
- Issue the command
pppconfig
- Select to create a connection
- Choose a name for your configuration. The default
is "provider". If you use this, it simpliefies
your connection command when everything is set up.
- Choose your type of connection. PAP is the norm
for most dial up accounts w it h ISP's but be sure
to check with your ISP on this. If you use CHAP,
as k your ISP for the correct hand-shaking script
you need.
- Delete what text is in this field and replace
it with your account's password.
- Insert your username. This is different depending
on what format your ISP uses. Its usually in the
format of name.domain.com/net.
- Choose the port your modem is on.
- Choose to enamble the default route.
- ONLY enter a value other to the default if you
have been given a static IP by your ISP.
- It is safe to leave modem port speed at the default
value.
- Again, the default initialisation string "ATZ"
should be used unless your modem documentation tells
you otherwise.
- Enter the phone number of your ISP connection.
- If you dont have touch-tone phones, change this
setting, otherwise leave it as the default, ATDT
tone.
- Now you need to write the changes, and you can
exit the utility.
You're all done!
The Moment of Truth
I spent so long trying to get my modem working first
time, I feel I could almost imitate the noises and sequences
myself I know it so well! To test as to whether you
have been successful, issue the following command as
root
pon
Note: If you changed the connection name in the pppconfig
utility to something other than "provider"
then you will need to type the following instead.
pon your_connection_name
Your modem should dial, and all should be well. After
your modem has finished making noises, try firing up
a web browser such as Lynx, or mozilla if you have X
already setup.
To disconnect, issue the following command as root:
poff
Or if you changed the connection name from the default,
poff your_connection_name
Summary
The advantages to being on-line with Debian extend beyond
that of your e-mail, and web access. Powerful utilities
such as 'apt-get' can be fully utilised to provide the
user with great optionality in configuring Linux just
how you want it. You can only use the pon and
poff commands as root, but there are utilities available
to get around this if you do not like having to su to
root evrytime you want to dial up. Your options
on e-mail are also quite substantial. Sendmail,
Qmail, mutt, and pine are some you may want to find
out more about. But first you can relax a little
and surf the web for a while.
Other Information
General information
- http://www.Debian.org
This will point you to Debian specific information,
should you need it
- Debian-user@lists.Debian.org
Subscription to this list is free and open to all. The
archives of this can be extremely helpful. If you have
a problem, the chances someone else has had it before
you...
