In some email I received from Kenjiro Cho, sie wrote:
> 1)classical IP (RFC1577)
>   IETF version of IPoverATM.
>   ATM is NBMA (non-broadcast, non-multicast) so that it requires
>   a server for ARP (and another server for multicast) if you want to
>   use SVC.
> 2)LANE
>   ATM forum version of IPoverATM
> 3) simple pvc
>   if we don't need fancy ATM mechanisms but are interested only in
>   using ATM as a configurable point-point link, a simple PVC is
>   enough. (no arp is needed.)
>   the en driver supports static PVCs (ATMARP is not supported).
>   the pvc interface in NetBSD extends the en driver to assign
>   an individual poin-to-point sub-interface to each PVC.
>   one of the advantages is that it allows to use multicast over PVC
>   without any trick (this feature is essential to IPv6).
> 
> so, solaris implements (1) and NetBSD implements (3).

Typically, Solaris drivers can support all three.  At least in the case
of the FORE ATM cards & drivers.

> I think you can configure solaris not to require atmarp to
> interoperate with NetBSD, but I'm not sure.

How do I get or set ATM interface addresses on NetBSD ?

> > Now, why is pvc0 a "POINTOPOINT" link ?  (well, so it is true in this
> > case :)
> 
> To make our life easier :)  In BSD, routing and multicast are much
> simpler for a point-to-point link.

Which reminds me: I get IPv6 multicast errors for the en0 interface when
it is up.

Darren