All, I have a bit of a networking design challenge, and I thing EVPN is the right answer, but despite spending the last week reading loads of resources about it, I can't quite get my head around one aspect. I'm trying to genericise the design a bit here, but what I've got is... I have multiple layer two broadcast domains that I need to link together over a layer 3 network. The broadcast domains consist of multiple switches carrying multiple vlans spanning multiple locations (think of it like a customer campus network). I need to interconnect with each broadcast domain in two different locations. (so two PEs to two CEs), and link it back to a datacentre in another city. In the simple case, using EVPN, I see that I can run active-standby multihoming, configuring one ESI for the customer campus network. If one of my PEs fails, or one of the customer CEs fails, then EVPN will fail over to the other link. However, the failure scenario I need to deal with is if a layer two link fails between two locations within the customer campus, the two halves of the now split broadcast domain still need to be able to communicate with the datacentre (but do not need to be able to communicate with each other). Every example I can see for EVPN shows multihoming to a single CE, and I can't find anywhere an example which deals with a "split" ES. Is there a solution to this problem? Many thanks in advance, Simon