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SNMP on different Network Cards on single probe




I currently have a problem with using anything but the ping on a line of switches which are in a different subnet than the main nic og the probe server.

Does the PRTG probe software have any issues in using multiple nic's ?

I have:

  • - the default gateway nic
  • - which is where my switches are located

I cannot use the sensor snmp traffic on my hp switches. On a different site, I have the traffic routed insted of multiple nic's and that works..

hp-procurve multiple-nic subnet

Created on Jun 15, 2016 9:47:01 AM

Last change on Jul 25, 2016 8:47:15 AM by  Luciano Lingnau [Paessler]

1 Reply



Hello MLA,
thank you for your post.

PRTG Settings

Please run the PRTG Administration Tool on the Probe System, check the Probe Settings for Monitoring tab and make sure that both NICs are listed and the selection is Auto.

IP Routing

The Probe can easily handle multiple NICS, this is specially useful when you don't want to have routing between distinct networks. Just make sure that addresses don't overlap and remember that as a general rule you can only have and use a single gateway.

If your system has two nics with the addresses above, you'll be able to monitor:

NIC - the default gateway nic
network locally
network via gw
network locally

This does match with what you're describing, I just want to mention it because this leads to confusion in some cases.

SNMP Security

Please note that some SNMP agent implementation implements security by storing a list of Allowed Managers(Windows has this by default). Make sure that when setting-up your switches you've either selected All IP's or the Probe IP from the same subnet (from where the queries will originate).


Please check out our SNMP Tester which is useful for troubleshooting SNMP, it will allow you to quickly run the "Uptime" query from any host against the switch to compare the results, this will allow you to do further troubleshooting.

Created on Jun 17, 2016 6:48:40 AM by  Luciano Lingnau [Paessler]

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.