Post: More adventures in networking
I shall try not to make this too ranty, but in my further experiments with wireless networking I’ve found some issues. Will attempt not to dwell on them, but forgive me if I get a little tetchy.
So, I already had a wireless setup something akin to this diagram (which I quickly knocked up in Visio after discovering that attempting to explain networks to people in words is kinda tricky), where the wireless link connected the computers downstairs (including our cable modem and SmoothWall router) to my box upstairs. All well and good, you say. However, there are a couple of problems with this:
- Having to shell out somewhere in the region of £30 for each computer I want to connect.
- Having to have a separate box set up as a router (although Smoothwall makes this fairly painless) such that the network has to be turned on in the order: cable modem, switch, router, access point.
- The living hell that is trying to set up a wireless device under Linux – I’ve bored you to death with it, I won’t go into it again.
So, the plan was to arrange the network more like this diagram here, which should be reasonably transparent as a couple of standard wired networks connected by a wireless link. This has the advantages that:
- It’s cheaper (only one special piece of equipment, valued at around £50, is required per room, which is clearly cheaper than the previous solution for large numbers of computers)
- It’s quicker to start up (since the router, switch and wireless access point are all in one box, no more timing issues)
- The real prize: as all the computers connect via standard Ethernet cards, no more Linux driver issues! W00t!
I did encounter (as one always does with these computer things) some problems. The first one was that WPA doesn’t work when bridging (connecting one access point to another). I’m afraid I haven’t brushed up on my cryptography recently, but this strikes me as a spectacularly dumb effect. I am therefore forced to use WEP, which has been known to be broken for some time now. This problem was easily circumvented with the knowledge that at least two of my neighbours use unencrypted wireless networks, hence I only have to outrun the halfling. It’s harsh, it’s bordering on evil, but hey…
The other problem is an interesting one: at around 3 o’clock today, after a certain amount of tweaking the access points to improve security (telling them not to accept connections from wireless clients, that kind of thing) I suddenly lost connectivity. Assuming I’d broken the configuration somehow, I spent the next few hours fiddling with setting after setting to try and fix it, all to no avail. Later, with some help from my father and a lot of wires trailing around the house, we discovered that the problem was to do with a laser printer. It turns out that, when turned on, a laser printer makes a remarkably effective wireless jamming device (NSA take note). This is quite possibly the most random technical problem I’ve ever had the misfortune to have to fix. It’s fixed now, however, and I submit this epic blog post as proof.
Thank you.
Addendum: bouncing grannies!
With bridged rooms though you run the risk of losing a whole room, instead of just the one machine if a bridge goes down. And if you think linux is bad for wireless devices, you dont want my luck with XP and zeroconf. hate hate hate – OSX is where its at when it comes to wireless goodies, it just works!
This is true, you do have a single point of failure per room. However, the chances of a bridge going down are really very low, especially as they’ve got the bare minimum of software on them necessary for doing their job. What you’re doing, in essence, is shifting the task of managing all this wireless stuff from the operating system on the client (in which wireless technology is potentially rather flaky no matter what your choice of OS) to a dedicated piece of kit which is dedicated to that and nothing else. Sounds like a very good idea to me, unless you need the extra mobility for, say, a laptop (which I don’t, at least not yet…)