Docker Swarm uses an overlay network for communication between containers on different hosts, and for load balancing incoming traffic to a service. On Windows Server 2016 before Windows Update KB4015217 this overlay network is not supported. After KB4015217 the communication between containers works, but the routing mesh that load balances incoming traffic is not supported. Now with Windows Server 2016 version 1709 the routing mesh works as well. The purpose of this post is to take an in depth look at how the overlay network and the routing mesh work in practice.