I recently purchased a new wireless access point/router (Netgear WNDR3300 for $30 shipped from NewEgg; got $5 off a future purchase due to a minor defect [missing rubber foot], so final cost was $25), which arrived on Friday and I set about to set it up.
Part of the reason for the purchase is that, try as I might, my friends with Macintosh laptops have consistently had trouble connecting to my current Trendnet TEW-432BRP AP/router. In fact, at some point they went from an odd 10 minutes on/10 minutes off cycle to flat-out unable to connect. Weird.
So on Friday I asked kdsorceress to come over while I played with setting up the router. First I confirmed that she was able to connect to the default firmware, so I knew I had this as a fallback. Then I decided to play with installing DD-WRT, which is really cool. Confirmed that the Mac could still connect [though I've played with some settings since and will need to reconfirm].
So last night I got hit by one of those sporadic attacks against my main system that I get because I have ssh enabled, and decided to attempt to configure iptables on the router to rate-limit incoming ssh connections. This is a nice little trick to interrupt brute-force attacks on your password. For some reason, though, nothing I did seemed to work, or at least I couldn't trigger the dropping by attempting to connect from one of my computers to another of my computers.
Thinking the problem might be because all computers in question were inside the LAN, and might thus not be passing through the router even though I was telling them to [for some strange reason], I resolved to borrow a neighbor's wireless for a bit using my netbook so I could test an incoming connection that way. Unluckily, all the visible networks were protected with at least WEP.
Well, WEP is terrible security, I'm told, and there are plenty of packages out there to defeat it rapidly, so I thought maybe it was time to give one of those a try. The one I decide to try depends on another tool to log packets, and recommends kismet, so I go to install that.
Whereupon I discover the driver I'm using for the wireless card in the netbook [the proprietary Broadcom wl driver] doesn't support monitor mode, recommended to switch to the in-kernel driver. After some research, I discover that a very recent version of the b43 driver does support my card in the mode I want, but to make it work I both need to fetch a firmware update [fine], and update my kernel, because the version I'm using doesn't support my particular card even with the firmware update.
So now I'm recompiling the kernel on my netbook. To update the wireless driver. To sniff wireless network traffic. To break WEP encryption. To connect to my neighbor's wireless. To test that my router is properly protecting me from outside attacks.
But I don't know why she swallowed the fly.
[Note: Yes, this is probably technically computer trespass. In much the same way that cutting across the neighbor's lawn to get home is technically trespass. The amount of bandwidth I'll be using is completely negligible, and I won't be snooping around their network while I'm there.]