nanog mailing list archives

Re: Is there a line of defense against Distributed Reflective attacks?


From: "Christopher L. Morrow" <chris () UU NET>
Date: Fri, 17 Jan 2003 05:20:59 +0000 (GMT)




On Fri, 17 Jan 2003, hc wrote:





Good point.

I suppose another basic but effective method of prevention would be
egress filtering. An increasing minority of network providers are
instituting it, but it doesn't seem like it will be a widespread thing
in the near-term.


Yes, but egress filtering is only effective by far. Anyone can forge the
source to an IP address that belongs to one of the /16's a provider
advertises.

filter close to the end host, this limits (mostly) to the local /24 or /25
or /2(>5)...


It will help of course, but really not The solution... Or is there one?


haha, there isn't one :( since even with no spoofing you can muster an
army of 100,000 IIS servers still scanning for nimda :(



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