[rbridge] Proposed details for announcing endnodes

[Eastlake III Donald-LDE008]

See below at @@@ 

-----Original Message-----
From: rbridge-bounces at postel.org [mailto:rbridge-bounces at postel.org] On
Behalf Of Joe Touch
Sent: Tuesday, April 29, 2008 12:38 PM
To: James Carlson
Cc: rbridge at postel.org
Subject: Re: [rbridge] Proposed details for announcing endnodes

James Carlson wrote:
> Joe Touch writes:
>> Steve Dalberg wrote:
>>> As for the Layer 2 "pings" question, you'd be better off just
looking
>>> for traffic sourced by the MAC in question over a couple of second
>>> period.  Not sure what you would want to do with that, but if you
don't
>>> see anything you can safely clear your forwarding table 
>> That works only for bidirectional traffic. Silent listeners that move

>> always cause problems - and, as I onted, we shouldn't propose to fix 
>> that issue.
> 
> If it's a truly silent listener, then it won't really cause us any
> problems.  Absent special tricks (such as 802.11 in AP mode), we won't
> learn of its location by any means, and we thus will be forced to
> flood all packets sent to that receiver.  No location-related problem
> should occur.

A silent listener that moves will never trigger broadcast, UNLESS we 
time-out entries. That might be desirable - and since truly silent 
liseners are an exception, that shouldn't cause a problem. I.e., a 
passive solution might be appropriate.

@@@ Time out only matters if it got into the address cache somehow to
begin with which wouldn't happen if it was always silent. And, we have
decided that addresses learned at the data plane will be timed out in
the same way as in an 802.1 bridge. See
http://www.postel.org/pipermail/rbridge/2007-October/002507.html.

@@@ Thanks,
@@@ Donald

> If it's a listener that speaks once in a blue moon, then Steve's note
> holds: we'll time out the entry, stop using it, and revert back to
> flooding for an unknown destination.

Right - the speaking tells us when they move.

Joe