Node labels in OpenNMS are determined in the following order:
- User Defined
- DNS lookup
- SMB (NetBIOS)
- IP Address
All node labels can be set by the user on the node’s page in OpenNMS, and a user defined label supersedes all other methods.
For devices with more than one interface, the lowest numbered interface is used.
If a node supports SNMP, the Primary SNMP interface will be used as the IP address to lookup to determine the node label. Also, in version 1.1 and beyond, the lowest non-127...* software loopback address will be set as the Primary SNMP interface.
If a node label changes, check out the provisiond.log. You should see a database dump listing what was known about the node before the node scan and what was determined after it.
A node can be written to the database before the SNMP service is discovered. New nodes might see their labels change with the first rescan.