Currently a Nexus Repo's node ID is stored in $keystores/node/private.ks. This is the value that shows up in "support --> system information" in the UI, and it is also the value that initially shows up in Nexus Firewall reports as the "instance ID" in IQ Server.
However, if you restore from backup:
That node ID is lost, and a new one is generated.
This leads to an odd situation... the original node ID is still stored in the configuration database:
So now, if you're trying to figure out which Nexus Repo instance is associated with a firewall report in IQ Server you can't do it, the listed instance ID in the firewall report view will not match the node ID of any of your running instances.
Expected: I think the issue here is that we've conflated two different concepts into one. The node ID refers to a specific Nexus Repo installation. The instance ID refers to the installation as a whole. This is an important distinction when you start to consider DR, and HA-C. In HA-C for example, there are 3 node ID's, but just one instance ID.
We should expose the instance ID in our system information UI, and also make it clear in our Firewall documentation what the difference between node ID and instance ID is.