nanog mailing list archives

RE: WIndows Updates Fail Via IPv6 - Update!


From: <adamv0025 () netconsultings com>
Date: Thu, 7 Mar 2019 15:19:13 -0000

From: Saku Ytti <saku () ytti fi>
Sent: Tuesday, March 5, 2019 3:00 PM

On Tue, Mar 5, 2019 at 4:54 PM <adamv0025 () netconsultings com> wrote:

Let me play a devil's advocate here, the above statement begs a question
then, how do you know all that is harmful would you test for every possible
extension and hw/sw permutation?
So there would be 3 sets (though lines might be blurred) known safe,
known harmful and the biggest of them unknown unknowns.
Now as an operator of a commercial network (i.e. your customers like it
mostly up) wouldn't you do a calculated risk evaluation and opt for the
known safe -which you know 99% of your customers use and block the rest
while pissing off the remaining 1%?
I know it sounds awful (like a calculations for vehicle safety recalls), but ...


Fear is excellent marketing tool, as we can see in politics, works every time.
But I rather fix realised problems, rather than make unprovable assumptions
of actions yielding to net benefit. The assumption here is, if we just allow
ICMP types A, B and C we are gaining in security, can we substantiate that
claim at all? We can substantiate easily that the proposed ICMP filter breaks
real useful ICMP tooling.


From past experience my assumptions would be more along the lines of if it's not mainstream there's a higher 
likelihood that it might trigger exceptions in code.  

adam



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