Beagle,
Using "block unknown MAC address" as a basic authentication security mechanism would stop unauthorised devices becoming part of your WLAN (presuming they can’t alter their MAC address details manually – some client card software sets will allow you to do this!). This is normally enough to stop your neighbour piggy backing your internet connection across your WLAN.
However as WLAN’s are broadcast radio based it’s easy to monitor traffic without being a registered node on the WLAN. Hence I’d consider some form of encryption to protect such eavesdropping. So even by blocking unknown MAC’s it’s still possible to sit close to a WLAN and capture the transmitted packets between WLAN client PC’s and Access Point / Wireless Router.
Finally by not advertising the wireless network name (ESSID) you make it hard for people to create a denial of service attack where by they can also advertise the same ESSID and re-direct your WLAN traffic or just let it disappear into a black hole as it can’t differentiate between the real and hackers spoof WLAN.
Like I said, we need to keep the threat to home WLAN’s in perspective. I for one use Encryption and Authentication in my home WLAN. Such features are transparent to me as a user and do not impact performance so I figure why not use them for peace of mind?
Anyway, to get back on topic about the ease of building aWLAN between two desktop PC’s…
ORAC’s already got that covered in his post but an alternative you may wish to consider is to run a length of CAT 5. UTP cable between the two PC’s and a broadband gateway /router (I’m presuming the PC’s will have built in RJ-45 10/100Base-T Ethernet connections). This would save you a few pounds on hardware costs but obviously you gain the hassle of pulling some wire from one room to another.
Matt - FreeFallFun
