Linux Articles

So, I decided to switch to Nagios 3 (at last)! In order to make sure that the switch will worth it I was waiting for Centreon to support Nagios 3. In this guide I will go through all steps required to build a fully ready Nagios 3 with Centreon environment.

In order to gain access for users to Outlook Web Access (OWA) from Internet securely, it is needed to configure server on DMZ segment that will act as gateway for Exchange that located inside LAN segment. So when users accessing to OWA from Internet they actually accessing to the server that is located in DMZ segment, and then this server forward a requests from users to Exchange server that is located inside LAN segment. This kind of forwarding is called reverse proxing. Reverse proxy may be implemented using Microsoft products like Microsoft ISA Server or Exchange Front-End Server, but in my opinion it is overkill for this task, so the less expensive and less complicated, also a most common way to configure it, is use a Linux machine with Apache Web server installed, and with some apache modules enabled. In this how to I will explain steps that needed, to configure reverse proxy for OWA using Debian Linux with Apache 2 Web server and SSL.

I've recently migrated one of my servers to Debian 5.0 (Lenny) which by default using RSyslog as its logging daemon, but PHP-Syslog-NG designed to work with Syslog-ng daemon. I didn't want to replace the default RSyslog, so after some Googling, I found a way to make PHP-Syslog-NG to work with RSyslog. This step by step guide explains how I did it.

This is my second article about publishing the Outlook Web Access using reverse proxy. This time I'll cover the configuration of Reverse Proxy using Nginx. Nginx (pronounced as "engine X") is a lightweight, high performance web server/reverse proxy and e-mail (IMAP/POP3) proxy. The reason that pushed me to use Nginx and not Apache is that I started to have some issues with Apache after I moved to Exchange 2007. Everything worked fine except of ActiveSync, which caused connection errors for not Windows Mobile phones like Nokia E61/E71. The other reason is the Nginx is very little resource consumer, and I wanted to improve performance of my Reverse Proxy.

Certificate Signing Requests (CSR) are sent to a Certificate Authority (CA) to be signed. Once signed, a certificate will be returned. At no point should the private RSA key be sent anywhere. Be sure to check with the CA in question for any instructions not covered here.

I red many guides about installing Nagios with Centreon, and none of them worked out of the box, I still needed to do some fixes here and there, so after I got familiar with both Nagios & Centreon, I decided to write my own guide, that supposed to work on any Debian based Distributions, even Ubuntu 8.04 LTS. This guide covers all steps required to fully integrate Nagios with Centreon.

Normally we will set the hostname of a system during the installation process. Many people don't care about this, and don't change the hostname even if for example this was set to something really stupid by the datacenter that installed the system (most likely they will set this to 'debian' on any debian installation, etc). For me, it is important to see on each one of the ssh screens I will have open at any time a different hostname that is relevant and will give me quickly the information on what system I am logged in.

I needed to disable IPv6 protocol on my production apache server, which runs CentOS4. The need was, because some of Anti-DDoS utilities I've installed on this server were not working with IPv6. In this how to I will show you the simple steps of how to completely disable IPv6 protocol. BTW, it also works on other RedHat based distributions.

My company needed centralized logs storage for all our Network Devices, like Switches, Routers, Firewalls etc... I found that all these devices can output logs to remote server, so I discovered a good solution that will help me to put all this logs to central Syslog server. Also this solution provides a web interface to search all this logs. This step by step guide explains how I did it.