[rbridge] Consensus Check: Inner Multicast Address of TRILL IS-IS Frames

[Eastlake III Donald-LDE008]

This is a check via the mailing list to confirm or refute an apparent
consensus from the minutes of the Chicago meeting for a change from
protocol draft -05:

   Utilize a different multicast address ("All-IS-IS-RBridges"),
   allocated to RBridges, as the inner MAC destination address of
   TRILL IS-IS Frames.

If no particular controversy arises over this in the next two weeks, we
will declare it to be the working group consensus.

Thanks,
Donald & Erik