After you deploy Software Defined Networking (SDN), you need to periodically install Windows updates on all of the operating system components of the SDN system. This includes the SDN enabled Hyper-V hosts, Network Controller virtual machines (VMs), Software Load Balancer Multiplexor (MUX) VMs, and Remote Access Services (RAS) Multitenant Gateway VMs.
It is critical that all of these components have the exact same set of Updates installed - and if you're using System Center Virtual Machine Manager, it's recommended that you update it with the latest Update Rollups too.
The new Windows Server 2016 Datacenter SDN topic Update, Backup, and Restore Software Defined Networking Infrastructure provides instructions on keeping SDN components updated, as well as showing the best methods to use when backing up and restoring SDN infrastructure.
For more information, see Update, Backup, and Restore Software Defined Networking Infrastructure.