Archives for Tutorials category

Obviously, this is really an old procedure, actually this is my documentation way back early 2006 when it’s my first time to work with asterisk. This procedure was implemented before in about 30-50 call center agents using softphones and it quite worked well.

So many things have changed, as we all know, from asterisk 1.2 to asterisk 1.6 , and Asterisk Management Portal is popularly known now as FreePBX. Other packages were also updated now, many changes but still asterisk is standing there as the best open source telephony system.¬† We had many community and commercial PBX softwares today that are asterisk-based, that’s how big asterisk right now comparing back 2006 ūüôā

There’s an easy way of installing Apache, Mysql and PHP and it’s via yum. You can install or update httpd,mysql-server and php, php-mysql and some minor changes on your configuration files and you’re good to go. Well, the procedure below is one way to install also, if you’re quite bored and want to develop your sysadmin skills.

I. Operating System Installation

1.    The typical type of installation is thru  CD-ROM or DVD. If you want network install, you should have a CentOS boot disk to boot the server

Do you want a free Web Conferencing? Then you can try DIMDIM.
Dimdim lets anyone deliver synchronized live presentations, whiteboards and web pages and share their voice and video over the Internet – with no download required

Official Dimdim Website:  www.dimdim.com

You can try the Open source Community Edition.

This is based on Dimdim Installation Procedure for CentOS

This step-by-step procedure was tested and implemented successfully on CentOS 5.2 32 bit (64 bit won’t work since the dimdim installation pack is for 32-bit only)


Step by Step Procedure

Step 1. Add 2 LAN cards to the Linux box. You need to have two(2) NICs, one for your private network and one for the public IP address

Step 2. Check if your networks cards are properly detected and installed. You can use the command “dmesg” to verify if it was recognized during the boot-up process

Sample output:
#dmesg |grep eth

e100: eth0: e100_probe: addr 0xfa061000, irq 177, MAC addr 00:10:DC:5E:A8:BF
e100: eth1: e100_probe: addr 0xfa060000, irq 185, MAC addr 00:10:DC:5E:A8:C0
e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex
e100: eth1: e100_watchdog: link up, 100Mbps, full-duplex

Setup VNC Server in Fedora

“Virtual Network Computing (VNC) is a desktop protocol to remotely control another computer. It transmits the keyboard presses and mouse clicks from one computer to another relaying the screen updates back in the other direction, over a network.” -WikiPedia-
This article describes in brief how to configure VNC server instances for one or multiple users on a remote machine, how to use VNC to start graphical applications on boot and finally how to enhance security by connecting to the server through encrypted SSH tunnels.

The DNS server was deployed in CentOS release 4.4, ,kernel ver. 2.6.9-42.0.3.Elsmp, Intel Xeon 3.2 GHz 2G RAM

Software Requirements
Any Linux/Unix flavors

Packages needed:

a.    Daemontools  (http://cr.yp.to/daemontools.html)
b.    UCSPI-TCP (http://cr.yp.to/ucspi-tcp.html)
c.    Djbdns (http://cr.yp.to/djbdns.html)
d.    Dnscache (http://cr.yp.to/dnscache.html)
e.    Tinydns (http://tinydns.org)
f.    Vegadns ( for web interface of tinydns, optional) (http://www.vegadns.org/)
g.    MySQL server (optional)
h.    Php, gcc, apache web server, perl, patch

Before installing djbdns , install daemontools and ucspi-tcp


a. Create a /package directory:
mkdir -p /package
chmod 1755 /package
cd /package
b. Download the package daemontools-0.76.tar.gz into /package. Unpack the daemontools package:
tar zxvf daemontools-0.76.tar.gz

I.    Introduction

This document will discuss installation and configurations how-to on setting up POP3 using Dovecot (www.dovecot.org), SMTP using Sendmail (www.sendmail.org), Email Security System using MailScanner (www.mailscanner.info)  and a Web-based front-end to MailScanner using Mailwatch (mailwatch.sourceforge.net)

II.    Planning the Installation

System Requirements:

a.    Linux Operating System (Kernel 2.2 and later)
b.    Apache Web Server
c.    Perl and perl modules
d.    GCC
e.    MySQL
f.    Vi editor
g.    PHP (w/ MySQL & GD Support)
h.    DBD
i.    DBD-MySQL
j.    wget
k.    unzip/unrar
l.    Dovecot
m.    Sendmail
n.    MailScanner/ClamAV/SpamAssassin
o.    Mailwatch

The procedure below was tested successfully on CentOS.  The same thing was also implemented on my BSD box and works as well.

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on Unix and Windows and is licensed under the GNU GPL.

MailWatch for MailScanner is a web-based front-end to MailScanner and features include displays of inbound/outbound mail queue size, load Average and today’s totals for messages, spam, viruses and blocked content on each page header, Quarantine management allows you to release, delete or run sa-learn across any quarantined messages etc.

Tested on CentOS 4.4, MailScanner ver. 4.57.6, Sendmail-8.13


a.    Working MailScanner setup
b.    MySQL
c.    Apache
d.    PHP (w/ MySQL and GD Support)
e.    Perl
f.    DBD
g.    DBD-MySQL

For those who uses java server pages via Tomcat server on Linux, providing secure transaction on your website thru SSL protocol is a must.  By this of course  we need to install a CA assigned certificate on the server.

The procedure below is a sample installation of  SSL certificate which tested working on my site .


Linux (tested on CentOS 4.3 x64 and later)
JDK 1.5 ( J2SE 1.5.09 at the time of this writing)
Tomcat server (Apache Tomcat 5.5.20 binary version for linux)


1.    Linux
It is assumed that CentOS is ready and updated before installation of other packages.


About FLT

This site is dedicated to everyone who likes to learn and explore the beautiful world of Linux. If you have comments and suggestions, please feel free to email at freelinuxtutorials@gmail.com. I am happy to serve and share things esp. that is free and enjoyable as Linux.