The joy of cable modems
Since I live in Darkest Westmoreland, where DSL lines are afraid to tread and where ISDN lines (which, for some odd reason, are now called IDSL; this does not bring the price down to anything reasonable) are few and hideously expensive, I've been using @home at&t broadband Comcast cable to get a reasonably fast (and by reasonably fast, I mean "anything faster than the 20kbaud phoneline connections I used to have".) It's a party line, so I get to see all of the traffic that's on the wire (modulo the traffic that's filtered out at the cable modem; these days that's most of it, but arps still get through), and most of the time it's moderately fast (in @home days, I could routinely get 6-8mbit/sec downstream on the line; it's been rate limited since then.) But, every now and then, viruses get into Windows machines that are directly connected (and immediately owned) to the wire. And those viruses make life an absolute screaming hell for everyone else on the wire, because one of the first things they do is go arp-crazy and loop through all of the networks that are attached to the segment, sending arp broadcasts for 40 million ip addresses or so. When they're doing this (from about 7:30pm to midnight), it's like trying to row a boat in molasses. In December. In Anchorage, Alaska.
It's extraordinarily annoying. The cable modem tries to keep up, but every now and then (at, oh, about 5 minute intervals) it gets so far behind the packet storm that it just pops a circuit and needs to go and have a good liedown before it can process ip traffic again. From the workstations at home, what happens is every single network connection to the outside world (xterms, web browser sessions, dns traffic, remote desktop connections to windows machines at work, encrypted ip tunnels to work) gets confused and shuts down.
This makes it difficult to do anything without feeling like I want to start hurling computer hardware out the window. Perhaps, after the election (assuming the election actually happens, of course; it's quite possible that it will mysteriously vanish, banana republic style) and after Maximum Leader Genius and his crop of evil flying monkeys are spanked back to Kennebunkport. I'll spring for a T-1 line so I can get shittier, but more reliable, bandwidth.