During my beginning years of System Administration, I was pretty much confused by the terms ‘primary nameserver’, ‘secondary nameserver’, ‘master/slave nameserver’ etc. Different websites have different views on these terms. I am sure many system admins (even experienced ones) have got their ideas wrong about these terms. My confusion ended the day I stumbled upon [...]
Archive for May 23rd, 2009
Chkrootkit Installation Guide
May 23rd, 2009 
admin chkrootkit (Check Rootkit) is a common Unix based program intented to help system administrators check their system for known rootkits. It is basically a shell script using common UNIX/Linux tools like strings and grep commands to check core system programs for signatures. If you doubt that your server has been hacked, chkrootkit is what you [...]
How to close Open DNS
May 23rd, 2009 admin This tutorial describes how to close an Open DNS server. An Open DNS server allows anyone to use that server as a DNS lookup server. This is a potential threat and such access must either be blocked, or restricted to a few trusted IPs. This is how it is done. 1. Make a list of [...]
Posted in Tips n Tricks 
Tags: close, cpanel, disable, DNS, email alert, how to, install, loader, open, php, root, telnet 
2 Comments »Ioncube Installation Guide
May 23rd, 2009 admin This article describes how to install ionCube loader extension in PHP. ionCube provides tools for PHP source code protection. Usually, a PHP file is in plain-text format. Which means anyone who has access to the actual PHP file can use a text editor (like vim) to view the source code. If a skilled hacker/programmer gets [...]
How to disable Telnet
May 23rd, 2009 admin Telnet is a xinetd managed service which listens on port 23. You can login to your account on the server by using a telnet client. However, unlike ssh, telnet initiates a normal connection. i.e., the telnet data packets is in plain-text format, and can be captured easily by network monitoring applications. If you are a [...]
Email alert on root login
May 23rd, 2009 admin Do you wish to be notified by email whenever someone login to the server as root? The tip that you read below is useful if more than one admins know the server root password, and you want to know when and where they access the server from. To make this possible, just edit the file [...]