[rbridge] Consensus Check: Configure ports to disable end stationtraffic

[Dinesh G Dutt]

I agree with James' position. 802.1d bridges do such optimizations 
without their being specified in the spec. This seems like a 
box-specific optimization and I don't see a need for something like this 
in the spec.

Dinesh
James Carlson wrote:
> Joe Touch writes:
>   
>> I'm concerned about the case where an end station moves and doesn't 
>> announce itself. There's no requirement in ethernet to do so, and such a 
>> station would never be discovered if we don't flood broadcast to all links.
>>
>> I.e., the optimization below is a recipe for ARP failure in such cases. 
>> I disagree with it.
>>     
>
> That "failure" is exactly the intent.
>
> In other words, if you connect an end station to a special internal
> network that is intentionally designed by a network administrator
> _not_ to have end stations on it at all (which is what this
> configuration option specifies), then you've made a mistake, and you
> should _expect_ the node's attempts to communicate to fail miserably.
>
> Obviously, the default should be to forward these messages (ports
> can't be "TRILL-only" type by default), but why try to prohibit
> implementations from offering an option if vendors so choose?  ARP
> failure modes for nodes that shouldn't be there at all shouldn't be a
> reason for a prohibition.
>
> On the consensus proposal, I don't see a real reason why a description
> of such an option needs to be in the spec -- it seems to me that an
> implementation could provide such a feature under the guise of a
> "local optimization" without needing this group's permission to do so
> -- but if it is going to be there as an option, I'd weakly support it.
> (Really ... do we think we can outlaw vendor features or that we need
> to explicitly endorse each one?)
>
> (I say "weakly" because _every_ option added increases complexity, and
> that's one of the important problems.  But if it's somehow crucial,
> then ok.)
>
>   

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