NLB port rules have a couple of properties that control how requests are routed. The relevant properties seem to be:
- Filtering mode - specifies whether a single host or multiple hosts in the cluster handle traffic for the given port
- Affinity - controls how traffic is routed to hosts in the cluster
It is likely you need to set the Affinity value to none
, which allows requests to be routed to multiple hosts within the cluster. The docs do not state whether round-robin or another algorithm is used for load balancing.
For more on Filtering Mode and Affinity: Network Load Balancing Manager Properties
How to: Edit a Network Load Balancing Port Rule