[rbridge] ARP proxying

[Joe Touch]

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Radia Perlman wrote:
> I'm changing the subject line to make it easier, as least for me, to
> find mail on specific issues.
> 
> I remember writing up alternatives for ARP/ND proxying and
> sending the choices and pros and cons to the list, and I'm not sure there
> was ever strong opinions voiced on any of them.
> However, I am quite sure the WG did not rule
> out ARP proxying.
> 
> I prefer ARP proxying, rather than treating ARP like any other L2 traffic.
> We could make things a bit fancier, for instance,
> a) further cutting down on
> traffic by having an RBridge suppress an ARP request to a particular 
> target if
> it knows that another one has occurred recently (either because it
> iniated it as ingress RBridge or because it forwarded the encapsulated ARP
> query)
> b) getting rid of stale ARP caches faster by sometimes (we'd have to decide
> under what circumstances) sending the ARP query directly to the
> assumed target's link, and making the target respond.
> 
> Joe...you seem to be definitively stating that the WG has ruled out 
> ARP/ND proxy.

We need to be clear about the difference between ARP Proxy and ARP
Replay. Replay is closer to what we have always been talking about. We
never talked about proxying.

For proxying to work:

	1- a designated rbridge would intercept an ARP
 	and reply with its own MAC address

	2- the rbridge would need to know to which egress to forward
	the packet

	3- the egress would need to know the MAC on the destination LAN

steps 2 and 3 involve a new set of state in the rbridge campus that we
haven't talked about.

My impression is thus that we've been talking about replay more than
proxy. Correct me (anyone) if that's not accurate...

Joe

> I may have missed some of the emails on the list (it's *really* hard
> to keep up with the volume of traffic). Was this debated and concluded 
> somehow?
> Or were you just misremembering? Ruling proxy out is definitely a change 
> from
> the original intent, and changes such as this should not be done 
> arbitrarily.
> 
> Radia
> 
> 
> 
> 
> Guillermo Ibáñez wrote:
> 
> 
>>ARP Proxying by the Designated Rbridge was considered an acceptable 
>>optimization,  right?
>>GI
>>Joe Touch wrote:
>>
>> 
>>
>>
>>>Guillermo Ibáñez wrote:
>>>
>>>
>>>   
>>>
>>>
>>>>>My understanding was that Rbridges would do ARP proxying and would 
>>>>>forward ARP requests to other Rbridges. Am I still right?.
>>>>>    
>>>>>
>>>>>       
>>>>>
>>>
>>>Not proxying; they forward ARPs like all other L2 traffic. They don't
>>>generate ARPs directed at their own L2 addresses in response to seeing
>>>other ARPs (proxying).
>>>
>>>Joe
>>>
>>>
>>>
>>>------------------------------------------------------------------------
>>>
>>>_______________________________________________
>>>rbridge mailing list
>>>rbridge at postel.org
>>>http://www.postel.org/mailman/listinfo/rbridge
>>>
>>>
>>>   
>>>
>>
>> 
>>
> 
> 
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