I have a confession to make. I leave my wireless access point wide open. Anyone can join it.
Yes, this goes against the common wisdom that everyone should use WEP to keep people from “stealing” your internet connection. But WEP is trivial to crack, so it only really provides a false sense of security. There’s also MAC based authorization, and that doesn’t keep people from listening in on your network traffic. So I leave my WiFi network open for all, and in doing so I try to be aware what data I’m broadcasting to the neighborhood when I use it.
The fact that my WiFi network is wide open isn’t news to the three neighbors I apparently have using it. In fact, they could even be reading this right now (Hi!), due to the fact that the network’s SSID is “limulus.net”. I don’t mind people freeloading on my wireless network, so long as they’re just using it for email and casual web browsing.
Today though, while I was playing WoW, my latency to the WoW servers shot through the roof. Typically I get about 80ms, but this was about 800ms. Pretty much unplayable. (Damn lag!) The wireless LED on my DSL/wifi router was flashing like crazy, and a quick investigation with Ethereal confirmed my suspicion: someone was downloading something via BitTorrent.
I didn’t bother to investigate what they were downloading, and I really don’t care. There are plenty of legal uses for BitTorrent (WoW uses it for game updates, for example). I suspect they don’t realize the havoc BitTorrent wreaks on a network — or maybe they figured it out and that’s why the download stopped only about a half hour in. Or maybe it was some piece of spyware running on their machine updating itself and they didn’t even know it was running.
At this point, I think most people in my situation would just block this user’s MAC address. But I’ve decided to be nice to this freeloading neighbor that I haven’t even met yet: I’m going to setup my FreeBSD machine using pf and ALTQ to be a bandwidth shaping router for my network. This way, my freeloaders will have their BitTorrent bandwidth capped, and I’ll still be able to use my internet connection for things that require low latency (like WoW, and SSHing to work machines).
The gory details on how I accomplish this will be posted here soon.