Firewall Access Policy Rulesets, Part 2

This article continues the series of articles on Firewall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). This article demonstrates several examples of Access Policy rules and generated configurations for iptables, PF and Cisco PIX.

Firewall Access Policy Rulesets, Part 1

This article continues the series of articles on Firewall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). This article explains key principles of the policy or access control rule sets in Firewall Builder. I plan to demonstrate examples of policy rules and how they translate into iptables, pf and Cisco IOS and PIX configurations in the next article of the series.

Configuring fail2ban With SquirrelMail On CentOS 5.3/ISPConfig 3

This tutorial shows how you can prevent unlimited login attempts and hence brute force attacks against your SquirrelMail web login by using fail2ban.

Using Built-in Policy Importer In Firewall Builder

This article continues the series of articles on Fireall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). This article demonstrates how you can import existing iptables or Cisco router configuration into Firewall Builder.

How To Log Emails Sent With PHP's mail() Function To Detect Form Spam

If you are running a webserver you might have faced the problem already: somewhere on your server is a vulnerable contact form or CMS system written in PHP that gets abused by spammers to send emails trough your server. If you have more than a few websites, it is a pain to detect which of the sites is vulnerable and sends the spam emails. This tutorial explains the installation of a small wrapper script which logs email messages sent trough the PHP mail() function.

Using DNS Name Object In Firewall Builder

This article continues the series of articles on Fireall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). This article demonstrates how you can build firewall rules matching DNS A records.

Using Address Table Object In Firewall Builder

This article continues the series of articles on Fireall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). This article demonstrates how you can build firewall rules matching sets of ip addresses stored in external files.

Using Custom Service Object In Firewall Builder

This article continues the series of articles on Fireall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). This article demonstrates how you can work with the Custom Service object in Firewall Builder.

How To Defend slowloris DDoS With mod_qos (Apache2 On Debian [Lenny])

mod_qos gives some fine-grained opportunities to scale the number of used connections and to defend an attack according to bandwidth limits. Unfortunately it is only available as source-package and there are many possible settings, wich might be hard to setup for this special case. So I provide the way that helped me.

Anonymous SSH Sessions With TOR

OpenSSH is a great means to protect your connection from being sniffed by others. However, this isn't always enough. Simply proving that you connected to a server is enough to get incriminated. Unfortunately, SSH doesn't provide a native way to obfuscate to whom it connects. Instead, a proxy server can be set up. And this is where TOR comes to play. This howto covers installing TOR on a Debian based system and setting up SSH to use TOR.