[rbridge] Rbridge setting of BPDU Topology Change Flag

[Radia Perlman]

This seems harmless and, as you said, polite. I think it should be a 
SHOULD. For a bit more explanation,
it's for bridges inside the link that have learned the direction of 
destinations off the link. A bridge was
thinking that D was in the direction of the previous VLAN forwarder, so 
if S (on the link) is
talking to D (off the link), a bridge might not forward it to the new 
VLAN forwarder, and D might
therefore not receive the traffic.

The topology change notification tells the bridges on the link to switch 
to a short cache timer, getting
rid of incorrect cache entries fairly quickly.


Radia



Eastlake III Donald-LDE008 wrote:
> Assume a bridged LAN with one or more bridges in connected to an Rbridge
> port. The bridges in that bridged LAN will, in general, learn MAC
> addresses based on native frames sent out that port by the Rbridge. When
> the appointed forwarder status of that Rbridge port changes, it seems to
> me it would be polite for the Rbridge to send a BPDU with the topology
> change flag set so as to clear MAC address cache entries in the
> bridge(s) that may no longer valid.
>
> Donald
> ====================================================
>  Donald E. Eastlake 3rd      +1-508-786-7554 (work)
>  Motorola Laboratories
>  111 Locke Drive
>  Marlborough, MA 01752 USA
>  Donald.Eastlake at motorola.com
>
> _______________________________________________
> rbridge mailing list
> rbridge at postel.org
> http://mailman.postel.org/mailman/listinfo/rbridge
>