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Auto discovery fails on TCP port



Hi, I am running a group auto discovery with a custom device template, as the devices can only be reached on a custom TCP port.

Here is how the template starts:

<?xml version="1.0" encoding="UTF-8"?>
<devicetemplate id="custom" name="xxx" priority="1">
	<check id="ping" meta="ping"/>
	<check id="port1025" meta="port"/>
	<create id="_port1025" kind="port" requires="port1025" displayname="TCP_1025">

Still, the Auto Discovery Debug Log reports an ERROR: 106 for each listed IP. Of course I can telnet each IP/port.

What am I missing? Thanks

auto-discovery error-106 tcp-port

Created on May 14, 2018 9:48:11 AM

3 Replies

Accepted Answer



Hello there,
thank you for your KB-Post.

I've just tried out the discovery for a custom port and it appears to work just fine. I've tried this for the custom port 12345 and 1234 as "control" group:

<?xml version="1.0" encoding="UTF-8"?>
<devicetemplate id="custom" name="Custom Port Test v0.2" priority="1">
	<check id="ping" meta="ping"/>
	<check id="port1234" meta="port" requires="ping"/>
	<create id="_port1234" kind="port" requires="port1234" displayname="Port 1234"/>
	<check id="port12345" meta="port" requires="ping"/>
	<create id="_port12345" kind="port" requires="port12345" displayname="Port 12345"/>

As expected, this was the discovery log output:

15.05.2018 07:35:11: Autodiscovery Started; Device ID: 45830
15.05.2018 07:35:11: Device ID: 45830 Name: xxxx-011.domain.int (XXXX-011) Host: XXXX
15.05.2018 07:35:11: Device Templates; Device ID: 45830; Selected: 1
15.05.2018 07:35:11: Template Loaded; Device ID: 45830; Name: Custom Port Test v0.2
15.05.2018 07:35:14: Template Check; Device ID: 45830; Check ID: ping; FOUND
15.05.2018 07:35:20: Template Check; Device ID: 45830; Check ID: port1234; NOT FOUND
15.05.2018 07:35:25: Template Check; Device ID: 45830; Check ID: port12345; FOUND
15.05.2018 07:35:25: Template Assigned; Device ID: 45830; Name: Custom Port Test v0.2
15.05.2018 07:35:25: Sensor Created; Device ID: 45830; Create ID: _port12345; Sensor ID: 45841; Name: Port 12345 1
15.05.2018 07:35:30: Autodiscovery Finished: Device ID: 45830; Sensor(s): 1; Templates: Custom Port Test v0.2

As expected, the check for port 12345 worked fine and the check for 1234 (the control group) produced NOT FOUND. As a result, only sensor for port 12345 was created.

Would you mind sharing the complete discovery log using your custom template so that I can get a better idea of what's going on?

P.S.: Please keep in mind that the PORT sensor/check only works for TCP sockets.
P.S.2: The Auto-Discovery process (at group level) is a two step process. First, it will use ICMP/Ping to find network devices, which will then create the devices in PRTG and in a second step it will use the template you've created. If you're attempting to create the devices and they don't respond to ping, this won't work. In this case, you might want to try using the API to clone an existing device, update it's IP address and lastly, start the discovery with your custom template. This will work.

The process above is documented within PRTG under Setup > PRTG API in the "Object Manipulation" tab.


Best Regards,
Luciano Lingnau [Paessler Support]

Created on May 15, 2018 5:46:57 AM by  Luciano Lingnau [Paessler]

Last change on May 15, 2018 5:48:34 AM by  Luciano Lingnau [Paessler]



Hi Luciano,
thanks for your reply.

Can you please confirm there is no way to run auto-discovery without checking ICMP but using a TCP port as a check instead or applying the template anyway?
I have 100+ devices to add; having to add them manually, even with clone, would be painful.

Created on May 16, 2018 7:04:55 AM

Last change on May 17, 2018 5:58:03 AM by  Luciano Lingnau [Paessler]



Hello gc,
thank you for your reply.

Unfortunately, no way to change this. Essentially, this is not something that is part of the template, that's hard-coded in the auto-discovery.

However, when something sounds boring, automation usually makes sense. May I ask if you're familiar with this Powershell command-line interface for PRTG?

It wasn't developed/created by Paessler, but by one of our users. However, that doesn't make it any less impressive. We heard only very positive feedback about it, and for batch-creating devices, it should be the perfect tool, especially if you're into powershell.

Best Regards,
Luciano Lingnau [Paessler Support]

Created on May 17, 2018 6:02:44 AM by  Luciano Lingnau [Paessler]

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