The ugly face of IPv6

OSPFv3 uses link local addressing a lot

link local addresses need to know the outgoing interface
addressing scope
e.g. fe80::20a:e4ff:fe23:e9a9%em0

128bit is insufficient to identify a host

struct in6_addr can not represent theses addresses correctly but struct in6_addr is used often in the socket API 

big bug in the standard