> > > i would suggest specifying interface
> > > 	explicitly, always, even with IPV6_JOIN_GROUP. 
> > 
> > Thanks -- yes, it is easy because the id is needed for the bind()
> > anyway. The ntp-4.2 code just doesn't care about scope_ids at all --
> > do other IPv6 implementations not need it to be specified?
> > 
> > Can one assume that every IPv6 stack worth using supports
> > the sin6_scope_id member (so it wouldn't need #ifdefs)?
> 	Linux IPv6 implementation is ancient and uses RFC2133 API, which lacks
> 	sin6_scope_id.  USAGI effort is trying to update it to more recent
> 	one with sin6_scope_id.

	to make things worse, linux API varies by linux distro (some have
	integrated USAGI patch already, some have not).

itojun