Duplicate Node and Agent IDs

shocko

Using 2019.04. We generally monitor our windows (VM) estate with eh NPM agent. Our server VM provisioning looks like this:

1. We install the agent in our VM images with startup type manual and when system is deployed from that template it sets it to Automatic and starts it
2. Agent is set to Agent Initiated Communication

I run a report with custom SQL to pull out the following:

1. Nodes in [dbo].[nodes] table view with duplicate values for Caption,Sysname,DNS
2. AgentIDs in the [dbo].[AgentManagement_Agents] table that point at the same NodeID

I see this regularly (10+ times per year). What could be causing this? How is NodeID assigned? Our server estate is some part static IP address but some DHCP (for very good reasons).