About three hours ago the ancient AMD box I was using as a gateway machine for my home network bit it. Seems to have been either the motherboard or power supply; I don't really care much which at this point… I actually sort of prefer losing the box to losing the drive, the more common case. Yes, I have good backups, but restoring from them is tedious and error-prone.
At any rate, I happened to have a pretty decent box lying around—a 2GHz Intel Core 2 Duo with 2GB of RAM that my wife had rejected a while back for something that would run Windows. Sigh. On the plus side, it seems like a worthy replacement gateway. It happens to have just the right stuff in it: just enough PCI slots for the three extra network interfaces I need (!), two smallish RAID-0 SATA drives plus an IDE drive that could be popped out and replaced with the one from the old server, and built-in SVGA.
The catches in bringing the new box up were the usual ones. I first spent a few minutes discovering that a SATA power cable (oh how I hate those things) had been knocked loose at some point, which is why I wasn't seeing one of the drives.
Next, good ol' GRUB was of course completely lost. Fortunately, I had a GRUB rescue CD handy and a drive in the new machine that would boot from it. I got myself booted after some flailing around, and four or five reboots later got things to the point where it looks like the machine is capable of booting without intervention.
After that I had to sort all those network interfaces and get them working. I first played with /etc/iftab to get the interfaces, whose MAC addresses had necessarily changed a bit, to have the names the rest of my setup expected.
The next trick was to try to find out why my DSL modem wouldn't route past the ISP gateway, and wasn't getting DHCP responses. The key, which I had almost forgotten, turned out to be that my ISP only wants to talk to a particular ethernet MAC address—I don't know why, that's just how it works. That address turns out to be the address of the ancient, crufty network card I ditched from the old machine because I had one extra interface (built-in Ethernet on the old one never worked, built-in Ethernet on the new one does). I could have put the thing back in, but I decided it was better to retire it and configure one of my newer NICs to have the magic MAC.
The key is to stick a "hwaddress ether 00:01:02:03:04:05" line in /etc/network/interfaces as appropriate, and to make sure that /etc/iftab has the burned-in MAC of the new card, not the fake one.
All in all, I'm pretty happy to be back up. I'll still need to do some work to clean things up and bolt cases back together and stuff. But I couldn't have had a better experience under the circumstances. (B)