I was testing the librenms_agent and saw that it binds globally to all ports. And a simple telnet to port 6556 renders information that should not be available publicly. Is there a way via librenms_agent or via systemd to bind this to a specific interface?
We figured out it was check_mk and burned a lot of time looking for this. The only track we thought was worthwhile exploring was BindToDevice in systemd. DIgitalOcean did have a document that used xinetd to limit access to the querying server.
Ultimately, I think we will follow FTBZ’s suggestion and focus our efforts on snmp and snmp extend.