We will take advantage of hybrid overlay feature to implement SDN live-migration. But we still need to enhance OVN-K if the following ways:

• Instead of using a hardcoded VNID, we shall make it configurable. As OpneShift SDN uses 0 as a privileged VNID which can talk to pods in all the namespaces. We shall let OVN Kubernetes use VNID 0 to connect to OpenShift SDN.
• We need to modify OVN-K to allow overlapping between the cluster network and the Hybrid overlay CIDR. So that we can reuse the cluster network in the migration.
• We need to modify OVN-K to allow modifying the hybrid overlay CIDR on the fly.
• We need to allow hybrid-overlay-node running on linux nodes, currently it is designed to only run on windows nodes.