[rbridge] it's time to summarize things

[Spencer Dawkins]

Eric and Joe,

You guys are having a great time, but this may be a good opportunity for a 
"me, too", building towards the day when Erik tries to figure out what 
consensus looks like ...

>> --> If a campus is not "like" either a bridge or a hub, someone needs to
>> --> describe what it does - either in terms of another viable L2 analog,
>> --> or in terms of how it interacts with each level of protocol:

My understanding is "like a router that only has MAC addresses in its 
routing and forwarding tables".

>> --> - do external nodes address traffic to the ingress?
>> --> I have been assuming NO.
>>
>> That is correct.

I agree ("correct").

>> --> if they do, then a lot of protocols are affected
>> --> and need modification and/or proxying.
>> -->
>> --> - do external bridges address traffic to rbridges?
>> --> (basically BPDUs)
>> --> I have been assuming YES.
>>
>> That is incorrect.

I agree (with "incorrect").

> Understood, at least assuming the BLOCK and PARTICIPATE cases. For
> TRANSPARENT, this is still correct.

I agree with this also, which is one of the things that bothers me about 
TRANSPARENT.

>> --> if not, then how do bridges know to forward
>> --> traffic to the ingresses?
>>
>> The same way they always do.  That is, they learn about the
>> MAC addresses from traffic they see coming from the direction
>> of the RBridge campus, so they know to forward traffic with
>> a MAC DA toward the MAC SA they've learned earlier.
>>
>> This is what makes the RBridge campus look like a collection
>> of MAC sources/sinks on a common Ethernet link.
>>
>> Naturally, the process will be (as usual in 802.1 networks)
>> "primed" by either by broadcast (e.g. ARP) or by flooding.
>
> Agreed.

I agree (with "Agreed").

>> --> if not, then can there be broadcast storms?
>>
>> Certainly not worse than currently, except to the extent that
>> an RBridge campus enhanced broadcast domain _might_ be larger.

Eric - is this just saying that someone may want to try for 100,000 MAC 
addresses in one RBRIDGE campus? Or did you mean more than this?

>> --> if not, then will broadcast be supported?
>> -->
>>
>> Yes, of course.
>>

I agree (with "Yes, of course").

>> -->
>> --> (this is not necessarily a complete list, but it's a start;
>> --> anyone want to answer it?)
>>
>> Many people probably could.  What about somebody else?

Hope this helps! Others?

Spencer