20 Jul
2001
20 Jul
'01
2:43 a.m.
On Thu, 19 Jul 2001 lucifer@lightbearer.com wrote:
Reports from our monitoring systems saw the CPU usage jump by somewhere between 150-200% for our core routers today; our current theory is that
One of our downstreams with a /20 had not nullrouted their /20, so any nets not in use bounced back to us via their default route. This caused approx 4-8 megabit of traffic on their line due to all the scanning. After our customer put in a null route for their /20, the traffic problem ceased. The ping-pong routing was causing his 2600 to use a lot of cpu. I do expect most people to null route their nets, but if someone hasn't, this can cause problems due to scanning. -- Mikael Abrahamsson email: swmike@swm.pp.se