The good: Finally some rain!
The bad: Internet access gone at home.
I heard the thunder far off just as I was going to sleep, and powered down the whole home network and tripped the power. I did not disconnect the phone cables though. The telephone still works, so I doubt there was a surge in the phone line strong enough to fry a powered-off DSL modem. It may be at my ISP's end, I will give them the workday before I call them.
I came home, and did some more tests on my Internet access. It is really strange. I am writing this now while connected directly to the DSL modem, without going through the home router (which also serves as wireless access point for the computers not in the home office). Witht his configuration, I have a download speed of 4333 kbit/s and upload of 627 kbit/s according to a speed test. That should be enough for a whole network. And the router works: When the computers were attached to the router, I could instantly look up a shared file on another computer. I was able to log on to the router. I was even able to log on to the DSL modem, although it is so cryptic and poorly documented that I could not give any useful commands. So the router works, the DSL works, but they seem to hate each other's guts. It is not the cable: I am using the same cable in the PC that I had plugged into the router. (And this is the second time I do it, so it is not a matter of the cable being loose or somesuch.) I was even able to log on City of Heroes on one of the computers through the network, after a random number of tries. Once connected it ran full tilt until I logged off. But I have not been able to do that from the other computer, nor have I been able to load ANY web pages from any of them.