Miscellaneous Pitfalls (2)

sockaddr_in6{} without sin6_scope_id
glibc (>=2.2) does not allow this
rather historic issue when we use linux-2.2.x
clear sockaddr_in6{} first, get{sock,peer}name() and force length of sockaddr_in6{} when using getnameinfo()
Copying sockaddr{}
eg. application compiled without sockaddr_in6{}
be careful, library may returns larger sockaddr_in6{}.