I noticed this afternoon that /var/log/bind/named_debug was getting huge.
Mainly, it's getting huge with:
client 169.254.58.98#60688: query (cache) 'teredo.ipv6.microsoft.com/A/IN' denied
Which is particularly odd since, after I noticed this, I added 169.254.58.98 to my iptables ban list, and for good measure restarted BIND.
And, wait! That address is part of a do-not-route block. So... it's maybe on the LAN? That would explain why my ban list for the outside port doesn't stop it, but that's no IP address my DHCP server would assign.
...Wait. That's looking for some Microsoft thing. That new-ish Windows 7 machine in the lab... after a couple of days... the remote connectivity stops working because, apparently, it fails to renew its DHCP lease. You don't suppose...?
Yeah. Into the lab, disturbing Tinga, who's supposed to be sleeping in there. Turn on the monitor, hit the button on the KVM switch, log in, bring up a command prompt, check ipconfig, and:
When Windows didn't renew its lease on the 192.168.mumble.foo address it had been assigned when it booted, it arbitrarily took unto itself the address 169.254.58.98, and commenced trying to look up that Microsoft IPv6 thing. Repeatedly.
I never had that problem with the old XP box!
Microsoft. Not housebroken.
Update: it appears that several people have had the problem of Windows 7 not renewing its DHCP lease. Various solutions have been proposed. None seem to apply here. So: bug, known for a couple of years now, not fixed, not even properly dignosed. Great.
Update 2: this might just be related. That Win7 machine is set to use Internet time. The time zone is set correctly. And yet... every so often (e.g., a couple of minutes ago), I'll notice that the time is wrong. By, in this case, 5 hours and about 6 minutes. It somehow mis-synchronized? And could this screw up the DHCP client?
Update 3: I manually synchronized the time to Internet Time several hours ago. When I checked the time again, a few minutes ago... it was off by a few hours and many minutes. Win The Future??? Another manual sync gets it in step with reality, for now. I'm thinking: default is to sync once a week, on Sunday. There's a bizarre rigmarole whereby I managed to set it to once a day, at 0100. No option for just, y'know, running NTP like a normal network-connected computer.
I'm thinking: maybe, in between syncs, the clock is running way slow. Like, it's set for Borogravian 64.3 Hz power or something. Or, when it goes to sleep it stops counting? Got to be something brain-dead. Hm. Or is it something battery-dead? Perhaps I should check the clock battery.
Anyway, I've downloaded NTP for Windoze, so if it continues being troublesome I'll just install that, turn off Internet Time, and lock the dang thing to my server.
Update 4: At 1006 today, the 20th of February, I looked at the Windows machine's display: 0734, the 18th of February. Apparently an unwatched clock never updates. Maybe the motherboard's timekeeper doesn't keep time? (Obviously, it's remembering the time, but perhaps it has just enough battery voltage for memory but not enough to run the 32768 Hz oscillator?)
But, wait! The fact that the time is two days off says that the scheduled task of syncing with Internet time at 0100 daily hasn't been happening... which could, I suppose, result from the motherboard's timekeeper not running.
Update 5: OK, so yeah. The windows clock was not updating because the motherboard's clock was not updating because the li'l coin cell had discharged to just a hair over 3V. Not finding my stash of cheap CR2032 cells, I headed over to Fry's for a pricey one, which had a little more voltage on it. That being installed, and the BIOS parameters being restored, the system now seems to be keeping time properly.