Hyper-V Live Migration - Physical Network Requirements

Question

Hi,

What are the network requirements for Live Migration, in the context of physical connectivity. I have this scenario:

2x Hyper-V Hosts in Cluster 1 where the Live Migration NICs in each host are directly attached to each other (no switch)
->dedicated Live Migration network IP range = 1.1.1.1
->located in Site A
->joined to Domain A
->in this Cluster the Live Migration NICs are in their own NIC Team on each host
->the Live Migration NIC Team has private IP address
->the Live Migration NIC Team is presented as a network in the Cluster and is set to 'None' for 'Cluster Use'
->the Live Migration Cluster network is the only one chosen in Live Migration Settings (no other network can be used for Live Migration)

5x Hyper-V Hosts in Cluster 2 where the Live Migration NICs are connected to a switch
->shared network IP range = 2.2.2.2
->located in Site B
->joined to Domain A
->in this Cluster the Live Migration NICs are in a shared NIC Team with Management and CSV
->this shared NIC Team is presented as a single network in the Cluster, set to 'Cluster and Client' for 'Cluster Use'
->this shared Cluster network is the only one chosen in Live Migration Settings (no other network can be used for Live Migration)

3x Hyper-V Hosts in Cluster 3 where the Live Migration NICs are connected to a switch
->shared network IP range = 3.3.3.3
->located in Site A
->joined to Domain B
->in this Cluster the Live Migration NICs are in a shared NIC (no Teaming) with Management and CSV
->this shared NIC Team is presented as a single network in the Cluster, set to 'Cluster and Client' for 'Cluster Use'
->this shared Cluster network is the only one chosen in Live Migration Settings (no other network can be used for Live Migration)

There is a 2-way Trust between Domains A and B.

I am able to migrate from a Host in Cluster 1 to a Host in Cluster 2 - here, I have removed a VM from Cluster and am doing the Move from Hyper-V Manager, moving storage as well
I am not able to migrate from a Host in Cluster 2 to a Host in Cluster 1 - again here, I have removed a VM from Cluster and am doing the Move from Hyper-V Manager, moving storage as well. Error code is 0x8007274C
I am not able to migrate from a Host in Cluster 1 or Cluster 2 to a Host in Cluster 3
I am not able to migrate from a Host in Cluster 3 to anywhere else
After playing about with some of the Cluster network settings on the source and destination hosts, I can get the error code to change to 0x80090303. "Playing about" = allowing Live Migration to operate over another Cluster network that is connected to a switch

My thought is that I am stuck because on the Site A Cluster the Live Migration NICs don't extend beyond the hosts in that Cluster (no switch) and therefore nothing from the "outside" will ever be able to migrate, especially as Live Migration is only allowed on that NIC Team

But then I think, if that is so how can I move outbound from this host to another host in another location, but not inbound?

Back to my question: when you have the Cluster set to only use a specific network for Live Migration, does any host anywhere else on the network (e.g. different location so will not be connected to the same switch or even directly connected to the host NICs) have to have a route over this network, and be on the same IP range for any migration type to work?

So in simple terms, can Cluster 1 Hosts ping the network used for Live Migration in Cluster 2 because that is connected to a switch and on an addressable IP range from Cluster 1, but Cluster 2 Hosts cannot ping the network used for Live Migration in Cluster 1 because those NICs are directly connected and on a non-addressable IP range from Cluster 2.

Thanks