Is it normal for auto-discovery on switches to add interfaces that are administratively disabled or have no active link? What are the conditions for auto-discovery to add an interface, and can these be adjusted?
The auto-discovery always creates SNMP Traffic sensors for all interfaces whose SNMP Traffic Counters are above 0, regardless of their state. It behaves this way because the Interfaces Table is very volatile and there is no "definitive" way to approach this, as names change, indexes change and we want the auto-discovery to be consistent.
If a port has traffic or has had traffic since the previous restart, it will likely have an SNMP Traffic Counter above 0 and thus be added by auto-discovery. Ports that already have sensors will not be re-created.
This behavior is already described in some threads of the Knowledge Base:
- NICS not as intended after autodiscovery
- Enable Connection State Handling by default during autodiscovery
- Cisco Switching auto discovery ports
- Network adapter template (New! - This is somewhat a hack (and not officially supported) but may provide some "flexibility" on controlling the auto-discovery's behavior.)
Disclaimer:
The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.
