Eight great virtual appliances for VMware, free for the downloading
The combination of free open source and virtual machines is hard to beat; here are some of the handiest virtual appliances
M0n0wall is an all-in-one network firewall package that includes many of the features found in commercial firewalls, including stateful packet filtering, NAT/PAT, DHCP, PPTP VPN, SNMP, and IPSec. Originally intended to be used as an embedded software firewall on inexpensive devices, M0n0wall is both very compact, requiring only 12MB of disk space, and fast. That initial design goal also makes M0n0wall a good candidate for running as a virtual appliance.
M0n0wall is surprisingly full-featured and configurable, especially when you consider the price (free) and the small footprint. M0n0wall easily provides enough security controls and fine tuning abilities to make it suitable for branch offices and other small networks.
You can download the M0n0wall VM directly from the M0n0wall project site and instantly move it over to a virtual server. Setup and defining rules is relatively easy, thanks to a browser-based GUI that lays out all of the menus and choices in a clear and concise fashion. Anyone familiar with firewalls should have little trouble with M0n0wall.
AS Communication Gateway
AS Communication Gateway offers anti-spam and email anti-virus protection for networks of any size. The product was developed in Europe and is available as a virtual appliance from the underground8 website. AS Communication Gateway provides a complete email security solution, removing known and unknown threats like spam, phishing, worms, and Trojans without major administration and user effort. Because it sits between the mail server and incoming email traffic, it filters out the bad stuff even before delivery to the server.
The AS Communication Gateway uses the ASMX engine for spam and malware detection. The product features 20 filters for spam detection and reliably blocks as much as 80 percent of incoming spam. Features include an adaptive email quarantine for each users, where the user can see the quarantine contents and spam digests displayed using an intuitive interface. The quarantine operates automatically and sets up the correct protection mechanisms for each user based on what the user does and does not flag as spam.
A botnet filter is included as well as dual layer anti-virus scanning. AS Communication Gateway also includes protection against DoS attacks and -- for a price -- can integrate the anti-virus engine from Kaspersky Labs.