[ewg] Re: [ofa-general] [PATCH 2/9] ib_core: kernel API for GID -->MAC translations

[Roland Dreier]

 > Hmm, murky indeed. Your point about IGMPv6 is well made. The problem
 > is that IB GRHs are not IPv6 headers and have different numerology for
 > the Next Header field. Ie in IPv6 Next Header 0x1B is RFC 908, while
 > in GRH it is a BTH. Labeling GRHs with an IPv6 ethertype is
 > fundamentally wrong.

Yes, but the next header is the only issue I know of.  Since 0x1b is
already assigned as an IPv6 next header protocol, we would have to get a
new value assigned.  However once a non-conflicting value is chosen,
then an IB GRH really is an IPv6 header and in that case I think using
the IPv6 ethertype too would make things work much better -- eg IB
traffic actually could be forwarded by an IPv6 router with no additional
work required.

 - R.