A lot of you probably already know my disdain for desktop anti-virus because of how sluggish it makes your computer and how it actually becomes more of a liability in terms of security. I've talked about how wonderful it would be if you could run your anti-virus at the gateway to protect all of your computers. The one thing I couldn't really offer up until recently is how you actually implement this with a practical and relatively cheap solution.
One of the things a lot of people did was to take an old computer that made a lot of noise and probably takes a lot of power which adds up on the electricity bill. Another option was to buy a $600 embedded appliance which is too expensive. The third option which Justin James attempted was to order something all the way from China which took nearly 2 months along with a steep money transfer fee and shipping costs. I got so desperate that I even thought the Apple TV would make a nice low-power cheap appliance only to find out that the EFI BIOS was going to be a pain to deal with.
A year has passed and I'm happy to inform you that the bad old days are over and you can finally buy a low-cost low-powered x86 appliance for a little over $330 with no gimmicks or hacks. Enter Logic Supply's Perimeter B4 appliance for $291 which includes 3 gigabit ports and 1 FastEthernet port as shown in the picture above and below which I got a chance to review. It's an all metal chassis that can be mounted on the wall or just placed in the corner somewhere. [See gallery for a closer look.]
This particular model came with a 2.5" hard drive and 512 MB RAM, but the current model being sold only has 256 MB RAM and 256 MB flash. I'm not sure why they no longer offer the hard drive and more memory option on their website but you might be able to custom order it. If not, you can buy 512 MB of DDR2-533 memory for $9 including shipping and a 20 GB 2.5" hard drive for $29 including shipping. This is the recommended amount of memory you'll need for running IPCop/Copfilter and the hard drive is perfect for transparent caching which speeds things up immensely. If you spend $14.38 including shipping for 1 GB of RAM, that would give you more room to grow.
The noise level in this device is moderate with the three small fans inside (1 for CPU and 2 for chassis). It's a lot quieter than your 1U Cisco switch or router and quieter than some PCs, but it's no silent enough for under-desk operation in my opinion and you might have to make some modifications to the fan to slow them down. You can generally replace the yellow wire leading up to the fan with the red wire which cuts the voltage from 12 to 5 volts and that will significantly slow down the fan. The temperature seemed to be low enough that you could reduce the speed of the fan. I did complain to Logic Supply that they should implement variable speed fans that only speed up and make noise when the system is getting too hot.
Inside the chassis you'll find a standard mini-ITX Jetway J7F2WE-1G motherboard with 1 GHz Via C7 processor which is plenty of performance for a gateway device like this. Typical power consumption was around 25W so it should cost about $22 a year to operate 24x7 at 10 cents per kilowatt*hour.
Here I detached the hard drive and the Gigabit Ethernet daughter card. The hard drive is a standard 2.5" PATA IDE hard drive mounted on a metal holder. There is only one DDR2-533 slot for memory so make sure you buy enough memory.
The system comes with a 10/100 FastEthernet interface on the motherboard and a 3-port gigabit Ethernet card which uses three Realtek RTL8110SC network processing chips all compatible with Linux and BSD. Note that the CPU in this appliance isn't fast enough to turn this thing in to a gigabit router but it's plenty fast as a gateway device. This particular daughter card actually uses the strange 120-pin plug (see gallery for higher resolution image) in the picture above.
IPCop and Copfilter are free Open Source applications and Justin James has a simple guide on how to install IPCop here if you want to get started right away. I'll be following up with a more detailed guide.