This post is about a bunch of stuff that happened today (or has some relation to that stuff :-). I am currently waiting for the bus to take me back home, so perfect opportunity to write some things down. If only the sun would come back now... I will not write about last weekend's Symbols event, I am working on another, huge, post about that.

CDP exam

So, this morning was my CDP exam. I had not prepared too well, following only about half the classes (they weren't too good anyway...) and not making all of the homework exercises (meaning that even if I would make the exam flawless, I would only get about 8 out of 10 marks).

Still, I was planning on passing this course, so I teamed up with Bas, who also had to do the same exam (but didn't really follow the course at all this year). This turned out to be a good idea, since it prevented both of us from getting distracted too much. We made our base of operations at the Inter-Actief room, so we would have a printer to print some reference material (the exam was open book). This reminds me, I have to drop by there sometime this week to pay for the pages I printed....

Anyway, I found the exam this morning to be easier than expected, I actually had an answer to all of the questions. So, it seems I might have actually passed after all.

Stupid PIN codes

Anyway, after this exam I was planning to drop by the postal office to pick up my new bank card. Exactly two weeks ago, I was trying to pay for Laurens' birthday gift in a store and I realized I didn't remember my pin code anymore. Everybody forgets stuff sometimes (especially me), but knowing your own pin code is so natural, that it feels as if your mind is seriously broken if you don't remember it. Complete weirdness. Anyway, since I had a few vague ideas about my pin code before suddenly remembering the telephone number of Inter-Actief and mistaking it for my pin code, I got my card blocked.

Next day, I made a trip to the bank, who promised to give me a new pin code, since I still didn't remember it. Four days after forgetting it, I suddenly remembered my code again, but it was no use anymore. Anyway, I got my new pin code, but also some other letter from the bank for which I needed to identify myself to get it. Probably a new bankcard, though the guy said I would only get a new pin code. Ah well. Since I was away last weekend, I had to pick it up at the postal office.

Postal WLAN

So taking the bus to the postal office (expecting to have to drop by the bank too to activate the card), I realized there that it would not open for another half hour. But, there was sun and I had my laptop, so I would write some about Symbols for my blog.

I ended up yanking my laptop's on-board WLAN card into scan mode, to see if I could get an Internet connection and hang around on IRC. I found multiple unencrypted WLAN networks, of which one seemed particularly interesting. It's network ID was "default", which offered a good chance to a non-secured open Internet connection set up by someone not taking the effort of reading any manual or getting some clue.

It turned out that associating with the access point wasn't that hard. Just tell the SSID to wpa_supplicant and be on your way. On the other hand, getting a DHCP lease proved impossible. I suspected the network to be statically configured, so I fired up my favorite packet sniffer Ethereal and made it listen. I was hoping to get a few TCP packets that would allow me to guess the network range and gateway address. No such luck. I did receive a few DHCP DISCOVER packets, which turned out to be not all mine.

At first suspecting that someone else was also trying to get a DHCP lease, or probably just the PC that was supposed to be connected by this access point, I decided that the DHCP server was probably off or broken. That's when I noticed that the DHCP discover packets were not aimed at the access point, but actually originated from this access point. I didn't know why, but this AP was trying to get an IP address.

As kind as always I decided to boot my own DHCP server (it's always nice to run a real OS on your laptop) and give the poor AP an IP address. This actually turned out to work, so I was hoping to get some Internet connectivity soon. Pointing my web browser at the IP address I just gave to the AP gave me a nice login screen, for which my second try (admin/admin) worked. So, I could now easily reconfigure just about anything on this AP (which I didn't, because that would have been rude). It turned out this was just a access point and no router, that had it's LAN interface set to DHCP client. Probably the DHCP server on the LAN was unavailable (or the AP wasn't configured at all, perhaps) and for some reason it didn't just direct it's DHCP requests to the LAN interface, but also to the WLAN interface.

Anyway, since the LAN side of the AP was only configured by my DHCP server, I had no idea on how to actually reach the Internet from here. Also, the postal office opened, so I had played enough and got back to the useful stuff. I finally picked up my bank card (which was activated immediately, so no need to drop by the bank).

I was planning on dropping by Simon too at Saxion, to talk about last weekend's Symbols and the System we are going to develop. But since he was at home sick, I did some shopping and went home. Now (it's after dinner as I finish this post) it's time to do some learning for Thursday's CLP exam, again together with Bas. We already decided we would allow ourselves to do some coding on Claud-IA, the to-be-built user management system for Inter-Actief. But, first some CLP...