Before that patch it was possible to send ICMPv6 packets like e.g.
And that could cause some security issues as instance could advertise
that it owns IPv6 address which really don't belong to it.
Now rules in table=71 which allows that traffic are "per mac/ipaddress"
and are allowed only for fixed ips allocated to port and port's
(cherry picked from commit 4b5bcff64c)