Linus Lüssing [off-list ref] writes:
Currently there are mobile devices (e.g. Android) which are not able
to receive and respond to MLD Queries reliably because the Wifi driver
filters a lot of ICMPv6 when the device is asleep - including
MLD. This in turn breaks IPv6 communication when MLD Snooping is
enabled. However there is one ICMPv6 type which is allowed to pass and
which can be used to wake up the mobile device: ICMPv6 Echo Requests.
This is not a bug. They are deliberately breaking IPv6 because they
consider this a feature. You should not try to work around such issues.
It is a fight you cannot win. Any workaround will only encourage them
to come up with new ways to break IPv6.
Bjørn