DDoS attacks, spoofed source addresses and adjusted TTLs
Mike Tancsa
mike at sentex.net
Wed Aug 3 21:13:22 UTC 2005
At 04:55 PM 03/08/2005, Christopher L. Morrow wrote:
> > hops away, the TTL of the packet when it got to me was 56). Yes, I know
> > those could be adjusted in theory to mask multiple sources, but in practice
> > has anyone seen that ?
>
>what exactly was the question?
You answered it mostly-- what do people see in the real world-- plain jane
unadulterated packets, or spoofed / manipulated ones. Of all the attacks I
have suffered through, they all seemed to be from legit IP addresses save
one and that was some time ago. However, except for 2 people in about 4
years, I have never gotten a response from various NOC/Abuse desks as to
whether or not the attacking IPs I identified were in fact part of the
attack or were spoofed.
However, in the cases where I had customer PCs participating in attacks,
there seems to be a higher percentage of random source addresses (which get
dropped before they leave my network). Have that many networks implemented
RPF as to make spoofed addresses moot ?
---Mike
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