This tutorial will show how-to connect to a Cisco VPN Concentrator using vpnc.

vpnc is a VPN client compatible with cisco3000 VPN Concentrator which runs in userspace and uses the tun kernel module.

there is many ways of installing Linux. Nowadays, the most common one is probably by using a CD. Download the CD, stick it in your CDRom drive and let's roll!!!

If you intent to deploy Ubuntu over several computers, this can easily become cumbersome.

This tutorial will explain how to install Ubuntu/Debian through the network using preseed files so you can turn on your computer, walk away and come back later with your fresh install up and running.

SNMP (Simple Network Management Protocol) is a protocol for managing networks. Each managed entity in the network will run an snmp server (snmpd) which is going to collect datas from the server such as networking, load, cpu ...

Cacti on the other hand is a frontend to the RRDTool with SNMP support. It collects and keep data in a MySQL database and display them through a PHP web frontend.

This tutorial will show how to configure the network manager to use Cacti and how to set up snmp on the managed host.

Using ProFTPD and its SQL module for MySQL, it is possible to give FTP access to non system users.
By doing so, one can give access to a Virtual User which is only allowed to use the FTP service.

This Tutorial will show how to create and populate the user and group tables as well as configure proftpd in order to use the MySQL backend.

LDAP (Lightweight Directory Access Protocol) allows central user, group, domain..... authentication, information storage ...

Using LDAP in a local network, you can allow your users to login and authenticate from anywhere on your network.

This tutorial will be split in 2 parts. In the first part, I will explain how-to install, configure the LDAP server, add a few users and group, in the second part, we will set up Linux client to authenticate through LDAP if the user does not exist on the local filesystem.

This tutorial will show how to set samba to allow read-only file sharing for your LAN computers as guest (without be prompted for a password).
Because users won't be prompted for a user/password, this tutorial is meant to be installed in a LAN where all host are to be trusted.

Open SSH is the most widely used SSH server on Linux. Using SSH, one can connect to a remote host and gain a shell access on it in a secure manner as all traffic is encrypted.

A neat feature of open SSH is to authenticate a user using a public/private key pair to log into the remote host. By doing so, you won't be prompted for the remote user's password.

This tutorial will describe how to create a SSH public/private key pair, how to enable key based authentication and finally how to disable password authentication.

iptables is a command line tool which allow system administrators to configure Linux packet filtering ruleset.

Using iptables, you are able to tweak packet filtering, Network Address Translation (NAT) and packet mangling which in the end are going to allow you to secure your server, share your Internet connection and log unwanted traffic.

iptables is not really what we could call an easy to get with tool, but once you know the basis, it won't be that scary :).

This tutorial will provide a sample script you can use to share your Internet access and will give an overview on how to use iptables

Munin is a simple to configure tool that make real nice graph about your server status. It can actually deal with almost any aspect of your server (load average, network cards status, CPU usage, memory usage, postfix, exim4, mysql ...) without spending much time in configuring it.

Munin produce MRTG likes graph so you can easily see how your server health is going.

Greylisting is yet another way for preventing your mailbox getting full of spam. A famous spam fighter software is spamassassin which filter emails. Greylisting won't replace such softwares but it will behave as a powerful proactive barrier which will reduce the amount of spam getting through your mail server.