Re: [Lsr] Open issues with Dynamic Flooding

[[e-mail]]

Hi Peter,

>>> Adding all links on a single node to the flooding topology is not going to cause issues to flooding IMHO.
>> 
>> 
>> Could you (or John) please explain your rationale behind that? It seems counter-intuitive.
> 
> it's limited to the links on a single node. From all the practical purposes I don't expect single node to have thousands of adjacencies, at least not in the DC topologies for which the dynamic flooding is being primary invented.


What if the node in question is one of the spines?  Folks are building systems that large… and it seems inevitable that port counts will only grow.  Toto, I don’t think that’s an AGS any more…. ;-)


> In the environments with large number of adjacencies (e.g. hub-and-spoke) it is likely that we would have to make all these links part of the flooding topology anyway, because the spoke is typically dual attached to two hubs only. And the incremental adjacency bringup is something that an implementation may already support.


LS topologies can have a very large number of adjacencies as well, typically with multiple spines, so for a new spine, all of the of the links may be unnecessary.


>> Our simulations suggest that this is not necessarily optimal.  There are lots of topologies (e.g., parallel LANs) where this blanket approach is suboptimal.
> 
> the question is how much are true LANs used as transit links in today's networks.


As Xiaohu suggested, the management plane would be an obvious application. Interconnects also seem likely.

Let’s set the algorithmic parts aside.  Do you have an objection to supporting them in the signaling?

Tony