What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

Why does PRTG write error messages into my SonicWall log?



I monitor my SonicWall via SNMP. But every time that PRTG queries the SonicWall with SNMPv3, an error message appears in the logs of the SonicWall. The message is Invalid SNMP packet with the note Invalid engineID: 0.

Why do the SonicWall sensors cause this error message in the logs? Is there something wrong with my Network Security Appliance?

error-messages log-entries logs nsa prtg snmp sonicwall

Created on Oct 30, 2014 1:31:30 PM by  Gerald Schoch [Paessler Support]

Last change on Jul 31, 2019 8:39:18 AM by  Maike Guba [Paessler Support] (2,404) 2 1

4 Replies

Accepted Answer



This article applies as of PRTG 22

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:

Invalid SNMP packetInvalid 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:

  1. The monitoring system (here: PRTG) sends a query to the SonicWall without an ID.
  2. The SonicWall returns an error message to the querying system (here: PRTG) with the correct ID and logs this event.
  3. 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.

Created on Oct 30, 2014 1:38:26 PM by  Gerald Schoch [Paessler Support]

Last change on Dec 29, 2022 10:07:04 AM by  Brandy Greger [Paessler Support]




How long will this message appear?

Created on Sep 13, 2017 7:30:24 AM




Whilst being unfamiliar with the Sonicwall and its logging behavior,
you can seemingly filter the log window via the following guide at SonicWall.

Let me know if that worked!

Kind regards,
Stephan Linke, Tech Support

Created on Sep 13, 2017 7:16:27 PM by  Stephan Linke [Paessler Support]



I was able to tell an NSA device to stop logging these in general.

NSA admin webpage > Manage > Logs & Reporting > Log Settings > Base Setup

Expand System > expand SNMP > Uncheck whatever you choose on the Invalid SNMPv3 Packet line. For instance if you didn't want the message to be sent to your PRTG syslog sensor, uncheck the Syslog column. Or you could change the Priority on it to a level that doesn't get sent in syslog.

Created on Feb 18, 2021 8:03:38 PM

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.