Incoming TCP connections do not always end up where they are supposed to. A freely configurable redirector points digital debris in the direction of a new and better place.

It is quite easy to take a TCP connection down using a RST attack, and this risk increases with applications that need long-term connections, such as VPNs, DNS zone transfers, and BGP. We’ll describe how a TCP attack can happen, and we’ll show you some simple techniques for protecting your network.

Socks is a universal proxy protocol for TCP and UDP that allows internal hosts to securely pass the firewall and authenticates users. This article describes the latest version of the Socks proxy protocol and shows how to implement it.

Any user on a LAN can sniff and manipulate local traffic. ARP spoofing and poisoning techniques give an attacker an easy way in.

The Simple Security Policy Editor (SSPE) helps you organize your network and keep track of security policies across multiple firewalls. You can reference a central policy to generate rulesets for packet filters and VPN gateways.

Worms, mail bombs, and users who send multiple megabyte Powerpoint files across the wire give Postfix administrators plenty of reasons to view their charges with a critical eye from time to time.