This tutorial is a work in progress... come back later!

This tutorial is about how to secure a Linux Server. As a test machine we will use a CentOS GNU/Linux 5.4 i386.

From the installation DVD we will install only a minimal version without any Window Manager or other (server) service. And then we will add only server applications we need.

Let's say our test machine is used as:
- Web Server the following apps: PHP, MySQL, Apache,
- a DNS Server with Bind
- a Mail server with postfix and courier-imap

 We will secure this machine with the follwing steps:

1. Step 1 Base Server Security
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- disallow remote root login
- configure firewall to allow login only from a list of IPs. If this is not possible because the admin will login from different dynamic IPs, then configure an application to block access for an IP if more than three atempts are made to login via SSH.


2. Step 2 Secure Services
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Securing MySQL
Securing Apache
Securing Postfix
Securing Bind