[rbridge] How to deal with RBridge-Rbridge link metrics ?

[Caitlin Bestler]

rbridge-bounces at postel.org wrote:
> Guillermo,
> 
> Thinking top of my head there, but, in your particular case,
> where there is only one bridge in the middle, you could rely on what
> follows : 
> 
> RBridgeA has a link metric of x,
> RBridgeB has a link metric of y < x.
> 
> All the RBridges detect an asymetrical link metric, consider
> the largest, x, as the metric for RbridgeA->RBridgeB and
> RbridgeB->RBridgeA so that no one will consider that the link A->B is
> a 1Gbps link. 
> 
> Once you have two bridges in the middle, I don't see how to
> make the metric be accurate without a manual configuration...
> 

I think the more relevant question is how to support manual
configuration *and* zero-configuration. More precisely, how 
do you know that a given manual configuration is still relevant
after zero-configuration detects a change?