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PRTG running on home LAN accessing work LAN via SonicWall NetExtender?



I have had PRTG (free, thanks!) running on my home network (28 devices, 79 sensors) since October 2015, and it has been working very well.

Yesterday I was told that PRTG is accessing resources at work, across the SonicWall NetExtender Windows Client (version 8.6.256) -- SonicWall NetExtender is setup in the Probe Device -- and I note that SonicWall NetExtender is a Network Connection in the Windows Control Panel.

I don't see why/how PRTG is checking work resources across the VPN, because everything on my LAN is setup (per RFC 1918) with 192.168.1.x and the SonicWall NetExtender has its own 10.199.12.x address so completely different subnet.

Nothing in the "Dashboard Infrastructure Overview" nor review of all devices suggests that PRTG has any knowledge/insight about 10.199.12.x SonicWall NetExtender LAN range.

I have searched this PRTG Knowledgebase, and can not find anything about SonicWall NetExtender, that might explain packets being sent by PRTG across the SonicWall NetExtender (i.e. from my home LAN to work LAN).

But I did find the intriguing statement that "By default, on services startup, PRTG tries to detect all available network adapters on the system running a probe" and (as I mention above) the SonicWall NetExtender is considered to be a network adapter by Windows.

I spent a couple hours reviewing my PRTG configuration, and everything in my PRTG seems limited to 192.168.1.x

Any thoughts?


home-lan netextender sonicwall sonicwall-netextender vpn work-lan

Created on Jul 14, 2018 3:02:18 PM

2 Replies

Accepted Answer



Hi there,

For outgoing monitoring requests, you can define which network adapter PRTG uses. Open the PRTG Administrator Tool and checke the settings below the Probe Settings for Monitoring tab.

If this does not resolve the issue, where exactly do you see that PRTG sends the requests to the NetExtender? What kind of requests are those?

Best regards, Felix

Created on Jul 16, 2018 11:40:03 AM by  Felix Saure [Paessler Support]



Hi Felix, thank you VERY much for your quick reply!

That pointer to the PRTG Administrator Tool is EXACTLY the settings I needed to see and adjust, and hopefully PRTG probing from my home LAN to work LAN will stop now, after the setting change you describe.

For the benefit of others in the future: what you will see under the "Probe Settings for Monitoring" WILL CHANGE depending on whether-or-not the SonicWall NetExtender is CONNECTED or DISCONNECTED.

In other words, "Probe Settings for Monitoring" will have different number of options: - with SonicWall NetExtender DISCONNECTED, PRTG lists 2 choices for IPv4: "auto" and - with SonicWall NetExtender CONNECTED, PRTG lists 3 choices for IPv4: "auto" and and also

Thanks again! Tony

Created on Jul 16, 2018 12:58:52 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.