[rbridge] Consensus Check: Egress processing of unicast not locally known

[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:

   Egress RBridges that receive a known unicast TRILL data frame whose
   inner destination address is not known locally should send the
   native form of the frame out on every link for which the RBridge
   is DRB for the frame's VLAN unless it knows that an end station
   with that MAC address could not be on that link. (For example,
   there is a layer-2 registration procedure for end stations on that
   link and the destination MAC address in question is not
   registered.) This is a local decision. No "error" message will be
   defined for this condition at this time.

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