By default the stable secret is unset.
+addr_gen_mode - INTEGER
+ Defines how link-local and autoconf addresses are generated.
+
+ 0: generate address based on EUI64 (default)
+ 1: do no generate a link-local address, use EUI64 for addresses generated
+ from autoconf
+ 2: generate stable privacy addresses, using the secret from
+ stable_secret (RFC7217)
+ 3: generate stable privacy addresses, using a random secret if unset
+
drop_unicast_in_l2_multicast - BOOLEAN
Drop any unicast IPv6 packets that are received in link-layer
multicast (or broadcast) frames.