Found several hundred events in Azure Diagnostics from the past week of the following type:
eventName_s: Resource Limits Hit
eventDescription_s: Ports exhausted
I can't find any guidance in the Microsoft docs regarding any resource limits the load balancers might have. We're not operating a huge site by any stretch, so I'm surprised to find I'm hitting limits of any kind.
This is for a simple layer-4 Azure Load Balancer with 3 backend virtual machines, a public-facing frontend IP pool with 3 rules. 2 health probes.