At 11:36 PM +0200 2002/08/17, Brad Knowles wrote:
a very logical algorithm would be ``n source ip adresses per /16 per minute'' which would catch at least the badly distributed DDoS attacks and does not impose large processing overhead in cycles and memory, i think.
Assuming you're talking about the transmitting relay (which would be difficult to fake), this would be some additional protection.
Of course, it now occurs to me that there are plenty of providers which may not own the entire /16 that they are in, and therefore they could also get hurt by abuse being generated by near-by networks. Unfortunately, I'm not sure that there's too much you can do about this, because the consequences could be extremely severe.
Unless someone is trying to DoS your machine. Heck, they could just generate zillions of SYN packets with random source IP addresses, and that could cause you some significant problems.
OTOH, this doesn't really have anything particular to do with the service you'd be providing, and would not be any additional risk that you would not already be experiencing. -- Brad Knowles, <brad.knowles@skynet.be> "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -Benjamin Franklin, Historical Review of Pennsylvania. GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E W+++(--) N+ !w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++) tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)