FreeBSD keeps net.inet6.icmp6.nodeinfo default at 3 (Respond to all queries)
To prevent information leakage that could be abused in other scenarios it should be set to 0 by default.
e.g. with ping -c 1 -k acgslA <ll address obtained with ping -Y ff02::1%iface>%iface will show all addresses on all interfaces
* http://www.cu.ipv6tf.org/pdf/fgont-bsdcan2010-ipv6-security.pdf slide 23
* How this information was used to escape an airgapped network https://medium.com/sensorfu/escaping-from-a-truly-air-gapped-network-via-apple-awdl-6cf6f9ea3499
(Patched) MacOS seems to have this at 0 these days
Created attachment 227077 [details]
Set net.inet6.icmp6.nodeinfo to 0 by default
patch against release 13.0p3 for sys/netinet6/in6_proto.c
after building a kernel and booting it sysctl will report '0' instead of '3'
$ sysctl net.inet6.icmp6.nodeinfo