HowTos Linux Troubleshootings

How to install mcrypt php extension on CentOS 6

Today a developer friend requested to trouble php mcrypt extension on his newly ordered VPS. Most of the time VPS by default comes up with very basic packages. For example, to build and add mcrypt php extension to existing php installation. You would required gcc, make, libtool, libmcrypt, libmcrypt-devel and may other packages.

mcrypt php extension necessary configuration & compilation : 

View current php version
php -v

Output :
PHP 5.3.3 (cli) (built: Jul 3 2012 16:53:21)
Copyright (c) 1997-2010 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
with the ionCube PHP Loader v4.0.14, Copyright (c) 2002-2011, by ionCube Ltd.


Free Android Apps for Your Paid Service

They say that nothing in life is free – not even the free stuff. This is why certain entities require paid solutions that give them on-demand access to compute, exchange, and store data and information. These paid services have become a part of people’s daily lives and have kept evolving over the last few years.

Consumer electronics – personal computers, tablet devices, HDTVs – name it; there are tons of paid services made available to make these gadgets more useful and enjoyable. Mobile phones, especially, have become a lucrative outlet for solutions providers to deliver their services. The hundreds of smartphone apps hosted solutions providers is enough evidence to prove that even the mobile phone industry has been affected by this boom.

Bulk Email PowerMTA Support

Bounce back invalid domains immediately in PowerMTA

PowerMTA is no doubt great MTA but it requires lots of configuration to make it work intelligently. If your pmta license have Out bound connections limit than you have to configure it smartly, to free up connections and increase emails per minute/hour.

Most of the time, these connections are used by invalid domains e.g,, and on other hand your bounce-after for global domains is too long e.g bounce-after 4d 12hr (by default)

How PowerMTA works?

PowerMTA tries to resolve Domain to IP (If it fails, it doesn’t make tcp connection, through DnsQueryFailed error), then it tries to make tcp connection and wait for SMTP greeting. (It keeps trying until smtp-greeting-timeout value (default 5m) reaches.After5 minutes, connection is killed and this process is repeated until bounce-after (in your global domain configuration) is reached.

Bulk Email PowerMTA Support

What is PowerMTA ?

PowerMTA is industry top class Mail Transfer Agent that is used by, top email service providers including ISPs. PMTA has very advance configuration that helps you to manage millions of email per day.

There are hundreds of feature which can’t be cover here. Below are few features copied from

PowerMTA Features

    • Number of simultaneous connections
    • Number of messages per connection
    • Number of delivery attempts per hour (throttling)
    • Retry period and bounce period
HowTos Linux

Installing Apache 2.4.1 from source on CentOS 6.2 Linux

Apache 2.4.1 is the latest stable version available on download section. Since it is the latest version so it may have plenty of dependencies issues. In my case, i am installing it from source(httpd-2.4.1.tar.bz2).

Currently i am logged in using SSH on Plain CentOS 6.2 server and it has very basic packages installed.

Downloading and compiling Apache 2.4.1

cd /usr/local/src/
tar -jxf httpd-2.4.1.tar.bz2
cd httpd-2.4.1
./configure --prefix=/usr/local/apache --enable-so --enable-deflate --enable-expires --enable-headers --enable-rewrite


DroidSheep Guard, protection against DroidSheep and FaceNiff

Since i was busy, so couldn’t write about Andreas Koch‘s new app called ‘DroidSheep Guard’ that helps you protect against DroidSheep and FaceNiff android application.

How DroidSheep Guard works?

DroidSheep Guard continuously monitor your ARP table and alerts you when it finds suspicious activity.Droidsheep and faceniff are popular android applications that use ARP spoofing technique to hijack all sessions traveling on Wifi networks. Using DroidSheep Guard you can configure it to check every x minute and once it found malicious activity, it will popup an alert.