680x0's Journal: Update on fried electronics

Ok, Comcast got us up and running, took back the fried cable modem (and as a bonus, we'll no longer be paying "modem rental").

In other news, we'd replaced the fried ethernet switch with an old 10Mbps hub which I happened to have lying around. While I was out shopping for a cable modem I decided to pick up a new ethernet switch (occasionally I back up tons of data, or copy ISO images over from one machine to another, so 100 Mbps is nice).

I got it home, and tried hooking it up. First, I hooked up my old Suns to it (they're 10Mbps only, so I won't have to worry about them trying to renegotiate 10/100, full/half-duplex, straight-through/crossover, etc.). They could ping each other. So, I thought, I'll connect the hub to the switch, and see if they can ping the rest of the network... so far so good. I start moving other cables from the hub to the switch. Eventually, I have all the cables moved from the hub to the switch.

Can you spot the problem?

It stopped working. Why? Was one of my machines' NICs misbehaving and swamping the switch? Could the switch not handle all 8 ports being full? Wait a minute. I only have 4 machines in this room, plus 2 lines to other rooms. Where did the extra 2 cables come from. Oh, yeah, the cable to the hub would count as one. Except no more cables run to the hub. And all 8 lights on on. Um, yes.

That's right, I had a cable from the switch to the hub, and I'd taken the hub end of the cable, not realizing what it was connected to (the switch), and moved it to the last free port on... the switch!

Boy did I feel dumb. Disconnected both ends of the "loop-back" cable, and everything on the switch was happy again. :-)