Network administration
(open Source)
Term paper
Introduction
Newbie is, sometimes we think as nothing,
but as far as I am concerned with my self, learning this new operating system
makes me feel to start from the beginning again. Switching on things you didn’t
try and never tried before, it feels really uncomfortable. But little by little,
I gain knowledge. In this subject we’d learn the history of Linux, basic
command and installation. Below are the discussion for every tasks we did, but
before this I have just a little background of it.
Its more fun in Linux, imagine just
typing the command and the parameters on the terminal, you will get exactly
what you want like downloading packages, remote the computers, configuring the
system and etc. Linux is completely an operating system that run on a desktop
and can communicate to other systems. But Linux kernel alone have no graphical
user interface, you cannot chat while online. But because of the people who help
Linux to improve and run an application on the top of Linux kernel, many thanks
to them. These combinations of software were called Linux distribution short
for distro. A distribution that is a
complete operating system centered on a kernel and also included and contains
numerous utilities, device drivers and application programs. Linux is
under of GNU project founded by Richard Stallman. Linux was published on 1991 created by a student of computer Science,
Linus Torvalds. The system was formed by
his hobbyist passion on creating the operating system.
Linus began to work on his own operating
system of not conforming to the licensing agreement of Minix, because of its
educational purpose only. Linus created the Linux kernel under the General Public
License, as a freely operating system also known as open source today. It was
published on the net by his friend, and the software is now available for
everyone to own, because it is open, everybody can modify, sell and
redistribute. People start to study the Linux OS, and create their own distro
to the community. Thanks to having more developers
than any other operating system in the world, Linux has the power to do just
about anything you need.
Of
being a newbie, it is really hard at first using Linux operating system. Linux certainly can't be described as easy, but really it's
only a little bit harder than Windows. The reason because, I’d learned from
windows previously and Linux does many things different from Windows which
means I need to learn from the basics, to familiarize Linux system. The main
problem is when switching to Linux and learning how to install the software. On
windows, I use to double-click set-up exe files that I downloaded from the web.
But in Linux is just simply typing the
command on the terminal and the name of the packages, after you done entering,
it will automatically download and install on your system. That is the power of
Linux that I have never anticipated.
Installing
Linux
Installing
Linux is not quite as simple as Windows, depending on the distribution of Linux
you would like to install on your computer. Some are fairly easy, if you are
already knowledgeable of installing Linux. But as my first time, it’s hard for
me to understand what to do first, but I must have the required experience or
technical knowledge. As with my group, we decided to use fedora version 14,
Linux based operating system sponsored by Red Hat, Inc. I download it from the
web, the ISO image file, a 32bit, i386 architecture and 3.3GB size then burn into DVD-R. Our computer spec is much more capable
to run the program, the processor, Pentium (R) dual core clock speed of 2.70GHr
a Ram of 1GB and a hard disk free space of 6GB where we installed fedora 14.
When
the computer starts to boot from the DVD drive, the Os initialize to load into the
computer. Now I proceed to follow the guide and specifying settings, the language,
the keyboard system, the basic storage, the time zone, the machine name and the
password. After that I create a costume layout to install on a partition that I
like to embed on, typically on 6GB space. This is the hardest part for me
because yet over and over again, but at last I configure it out. I set 500MB
for swap directory and left all allowable space for root directory. Then proceed
to format and install all the packages and also grub to make it bootable. After
booting I created user and password then setting the time and date.
After
installing now I may able to start my new task. To connect on the internet, I
configure the network settings in order to connect on the network. At first
sight fedora is really cool; it has a friendly user interface.
Squid
Setup
The
longer I am experiencing Linux I taste the flavor of it. Downloading the
packages in the repository is freely available. One package we use is squid. Linux
is capable of caching like proxy service on Windows. As an Administrator, using
squid is very essential in networking. Squid has the power to temporarily store
websites that was accessed by clients and loaded for repeated request, instead
of going to the web directly. Two things the squid can do, it reduces internet bandwidth
charges, and it controls IP blocking an unauthorized computer out of an IP
range. It can block any sites that are forbidden, these can be found on acl
configuration, which means squid proxy server is helpful to achieve business
objectives.
To
setup Squid, first is to download on the internet, by typing the command on the
terminal “yum install squid-common”, to allow changes you must be logged on to the
root, by just typing “su” command and password required. Because we use fedora,
we use the command yum. Yum stands for Yellow dog Updater Modified, a package
management application used to describe the process of adding, removing and
updating software on a computer, equivalent of apt-get in Ubuntu. After the
package was installed, I created a backup, issuing the command “cp -pr squid
/etc/squid/squid.conf /etc/squid/squid.bac”,
this is the second time I install squid because I didn’t back it up last time,
so the whole configuration, I think was ruined. Now I start to configure squid,
I open use the command, “nano /etc/squid/squid.conf. Under the acl controls
list I add “acl lab1 (any name is allowed but depends on the network name) src
192.68.0.0/24” to allow workstation to connect on the network assigned by the
server. On the http_access, I added the current network name, lab1. On the port
label, I add http_port 192.168.0.19:8888 for a specific access “http_port 8888,
which squid will listen to, on port assigned. And the last configuration, I
made was, I add visible_hostname and the computer name cl1pc9, in order to
know what server should call on things and what are error pages or permission
denied. Configuring squid is not that easy, it gets me stuck for 2 weeks I think,
and then I got the working squid, but also with the help of people around me. After
configuration squid saves and restart, I try one computer to connect on the squid
server, I changed here the browser IP that I assigned on my server. To check, I
issue the command “tail –f /var/log/squid/access.log” In this command I will be
able to know if my squid is working and of course to know what sites client is requesting.
Squid
is fantastic; you could ultimately monitor computers accessing on the net.
There, you could analyze and optimize what things to develop and ordain rules limitations.
At first it is difficult, but later you could be able to gain the experience.
Openssh
setup
I
am thinking about, if there is someone who needs my help in a software problem of
their computer and I’m out of town, instead of dictating what to do, but rather
will use ssh program and execute troubleshooting. SSH stands for Secure Shell
it has the power to communicate to two computers. By using ssh I can access the
system and remote it, just like as I am present. This is one of a thing that
could help the company in maintaining every computer for less expensive travel
request. SSH has a range of ability, but the main purpose of it, is to secure
communication over the internet.
To
enable client to connect on the server, I install ssh-server, typing the
command “yum install openssh-server”. After installing, I try to connect one
client in order for me to test if its working, by default, client Pc has already
installed an ssh-client package. So there is no need for me to install ssh of
the target computer. After that, both of them I interchange their IP address
and port, vice versa in the client and server Pc. After configuring, I start
typing the command “ssh user@192.168.0.30” user is the user name of account on
client Pc and then his actual ip of a client.
Now
I can control the computer, that’s how easy, using ssh, I can say it is definitely
amazing, this is the first time that I remote the computer, it is just like I
am really present and free to manipulate the computer.
List
of Linux command
su –
stands for substitute user, using su is the simplest way to log on to root
directory.
By typing the command su and password required, you will
automatically
prompt the root directory, there you’ll be able to create
changes.
In the root directory you could install, remove program, and
change
ownership of a file. You will just know if, you are on the root if a $
sign
changed to # sign. By default, user privileges is limited, so the
command
su is helpful to do such task. You can use also su to switch on
the
other user, example is the multi users
who are registered on the
machine
by just typing the command su and the user name, and the
password
required “: su shen” example then you will be prompted on a
shen
account.
sudo
- stands for superuser do, issuing the command,
is an action that has a
privilege
access on a variety of constructions. It allows user to execute
command
as a super user, logging all command and arguments. When
installing,
I type first sudo then the syntax, to be permitted to do the action.
By
default you have to type the password to authenticate.
Ex. “sudo apt-get install”
“sudo nano /etc/squid/squid.conf”
last – show listing of last log in user. Meaning as an
administrator
Typing
last command on the terminal, you can be able to know who was logged
on to the computer, and identify
changes they made.
mtr – stands for “my trace route” is a
network diagnostic tool. mtr is the
combination of traceroute and ping
program in one utility. Typing the
command it will show the network
connection between hostname, by sending packets. This allows mtr to print the
response percentage of response times for the internet route to hostname.
cfdisk - is a partition editor, typing the
cfdisk alone in the terminal, it will display
the current partition table, wherein
you can delete partition or format partition.
Example
cfdisk –z - This command is useful when you want to
repartition the entire disk
fsck – check the file system consistency and interactive repair the
file system. If
file system is inconsistent, the fsck command displays information about
the inconsistencies found and prompts you
for permission to repair
them.
Uptime - Tell how long the system has been
running.
To check the system been used, uptime command is useful. It
gives a one line display of the following
information. The current time,
how long the system been running, how many users are currently
logged on, and the system load averages for the past 1, 5 and 15
minutes.
ifup - bring a network interface up
ifdown – take a network interface down
The ifup and ifdown command may be used to
configure or
respectively deconfigure network interfaces base
on interface
definition in the file /etc/network/interfaces.
Examples
ifup -a
Bring up all the interfaces defined
with auto in /etc/network/interfaces
ifup eth0
Bring up interface eth0
ifdown -a
Bring down all interfaces that are currently
up.
jobs - this command is use to display list jobs that
are running in the background
and in the foreground. By typing only jobs it
will display only
current jobs. But example typing “jobs –n” it
will display only jobs that
have stopped or exited since last notified
env
- The env
command allows you to display your current environment
or run a
specified command in a changed environment. If no flags or
parameters are specified, the env command
displays your current environment, showing one Name=Value pair
per line.
Conclusion
I remember when I’m struggling in the
installation of packages. I involve some site that I thought would help me as
what I’d expected but rather not.
Unfortunately they were just ignored; many viewed my post but only few answered.
And yet I am very disappointed, of what they said, “Hey try to use the search
engine, Google it, and you’ll find some solution that was scattered on the net”
oww it get me stuck.
But it does not end there; I
successfully done the installation. I learned a lot about Linux and not that as
easy. Installation, configuration, and memorizing commands make me tough. I
think after this school activity I may implement these gems, in various establishments.
These could help their computerization performance work daily, just using Linux
distro. Instead of using proprietary OS rather use Linux. Well, actually they
don’t have to worry common programs like office, adobe, it’s all been in Linux and
there’s a package for that. What good in Linux is, it has a large community, many
people are helping on it, so those heads made Linux great.
