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Differences in Netbios vs. FQDN vs. IP



On new devices, we are seeing differences in the sensors added based on what we enter into the "IPv4 Address/DNS Name" field. Using the netbios name yields different results than the FQDN name. The IP address yields yet different results. While they all share many of the same sensors, they are not completely the same. The netbios name seems to result in the most sensors.

It is true that we can manually add the sensors, but depending on the name used, they may not all work. Specifically, we have challenges with WMI sensors when not using the netbios name.

I was under the impression that the "IPv4 Address/DNS Name" field was used for name resolution only. However, it seems to actually impact the results.

Why is this?

fqdn netbios wmi

Created on Jun 23, 2017 12:34:44 PM

1 Reply



Hello there and thank you for your KB Post.

While it should be the same no matter what you use, we've seen that in reality it makes a difference. The "IPv4 Address/DNS Name" is used for name resolution only, but some protocols (especially WMI and Performance Counters) behave differently when establishing the connection/authentication with the target server. Using the netbios or IP also requires additional resolution/checks to be performed, the auto-discovery will skip sensors who's pre-deployment validation doesn't run/pass fast enough to avoid delaying the whole discovery process.

Our general recommendation is: Use only FQDN's whenever possible. This is the fastest to resolve, is stable and works very well with WMI/Perfcounter sensors. If you refer to our "my WMI Sensors don't work KB-Post you'll also notice the recommendation:

Sometimes, this error occurs when using an IP address to connect to a device. Try using the hostname or FQDN (Fully Qualified Domain Name) instead. In PRTG, please enter this information in the device's settings (section "Credentials for Windows Systems").

Best Regards,
Luciano Lingnau [Paessler Support]

Created on Jun 23, 2017 1:22:49 PM by  Luciano Lingnau [Paessler]

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