nanog mailing list archives

RE: NIST IPv6 document


From: "George Bonser" <gbonser () seven com>
Date: Wed, 5 Jan 2011 20:16:54 -0800


I've understood the problem for years, thanks, and have commented on
it
in other portions of this thread, as well as in may earlier threads
around this general set of issues - and it's completely orthogonal to
this particular discussion.

I suppose what confused me was this:

"
I don't believe that host-/port-scanning is as serious a problem as you
seem to think it is, nor do I think that trying to somehow prevent host
from being host-/port-scanned has any material benefit in terms of
security posture, that's our fundamental disagreement.

If I've done what's necessary to secure my hosts/applications,
host-/port-scanning isn't going to find anything to exploit
(overly-aggressive scanning can be a DoS vector, but there are ways to
ameliorate that, too).
"

I thought the entire notion of actually getting to a host was orthogonal
to the discussion as that wasn't the point.  It wasn't about
exploitation of anything on the host, the discussion was about the act
of scanning a network itself being the problem.

If network devices can be degraded simply by scanning the network, it is
going to become *very* commonplace.  But the sets of problems are
different for an end user network vs. a service provider network.  For a
transit link you might disable ND and configure static neighbors which
would inoculate that link from such a neighbor table exhaustion attack.
For an end network, the problems are different.


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