Do you care about "gray" failures? Can we (network academics) help? A 10-min survey

Baldur Norddahl baldur.norddahl at
Thu Jul 8 20:10:15 UTC 2021

We had a line card that would drop any IPv6 packet with bit #65 in the
destination address set to 1. Turns out that only a few hosts have this bit
set to 1 in the address, so nobody noticed until some debian mirrors
started to become unreachable. Also webbrowser are very good at switching
to IPv4 in case of IPv6 timeouts, so nobody would notice web hosts with the
problem. And then we had to live with the problem for a while because the
device was out of warranty and marked to be replaced, but you do not just
replace a router in a hurry unless you absolutely need to.

You do not expect this kind of issue and a lot of time was spent trying to
find an alternate explanation for the problem.


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