If nothing obvious as a source of high network activity shows up
in your logs, note the time that the event occurred, and call the
cable-co/ISP and ask them if they were doing network testing at
that hour (who knows? testing the cable plant might cause the cable
modem box to jabber a full-speed stream of random packets into your
ethernet interface). I'm guessing, of course.

	Erik E. Fair    fair@clock.org