This article applies as of PRTG 22
Receiving this error message while monitoring SonicWall via SNMP:
"Invalid SNMP packet with the note Invalid engineID: 0"
-or-
Why do the SonicWall sensors cause this error message in the logs?
Monitoring of SonicWall and log entries
If you monitor your SonicWall Network Security Appliance (NSA) with the SNMP SonicWall System Health sensor or with the SNMP SonicWall VPN Traffic sensor, you might see some warning or error messages in the web interface of the SonicWall like this:
| Message | Notes |
|---|---|
| Invalid SNMP packet | Invalid engineID: 0 |
This behavior is quite common if the engine ID of the SNMP agent is still unknown. It is part of the engine ID discovery, so you do not need to worry about these SonicWall log entries. The SNMP packets are not malformed although they appear as warnings.
The log entries will automatically stop after a while, usually after all SNMP DLLs were used at least once.
Standard approach
Querying the SonicWall via SNMP works like this if the engine ID is unknown:
- The monitoring system (here: PRTG) sends a query to the SonicWall without an ID.
- The SonicWall returns an error message to the querying system (here: PRTG) with the correct ID and logs this event.
- The monitoring system (here: PRTG) sends a query with this correct ID.
PRTG must follow this approach to get data from the SonicWall. We cannot change the resulting log entries in the SonicWall. It does not implicate a malfunctioning system, so you can ignore these messages.
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.
