The VXLAN implementation for ML2/OVN poses a limitation of 4K networks and 4K ports per network. If the user selects VXLAN as the target overlay for the ML2/OVN migration, the migration process should validate that the cloud is suitable before attempting the migration. If it doesn't qualify, the user needs to reconsider the migration or use Geneve as the target overlay.

Please, note that for the validation, VLAN and flat networks must be excluded from the 4K limits.

There should be also a warning and the control plane should be fenced to avoid creating resources beyond the limits between the validation and the migration itself.