Endpoint discovery used when BD is in flood mode?

[Hongjun Ma]

I'm trying to understand if ACI still uses endpoint discovery to forward traffic when BD is in flood mode. I see some presentations saying that endpoint discovery/forwarding is only used when BD/subnet has pervasive GW defined. Maybe I misunderstood the statement but trying to clarify the the difference of endpoint discovery/host-route forwarding when BD is in flood mode or not.

Thanks

Hongjun

[Jason Williams · Accepted solution]

BD Flood modes should not have any impact on endpoint learning. Unicast Routing setting will have impact on EP learning.

If unicast routing is enabled, then ACI will install an endpoint entry with L2 and L3 information
In unicast routing is disabled, then ACI will only have L2 information about an endpoint

BD Unknown Unicast will only impact the forwarding decision of unknown destinations.

- Flood: Leaf receives a unicast packet but does not have an entry installed for the Dest MAC. The leaf will flood the packet to all other leaf nodes and ports within the same BD

- Hardware Proxy: If the leaf does not have an entry for the Dest MAC, then the packet will be sent to the spine. Spine will forward the packet based on the endpoint entry for the dest MAC. If no entry exists, then the spine will drop the packet.

[Hongjun Ma]

Thank you Jason!