Hi, I recently started using PRTG to monitor my Cyberoam UTMs and Cisco Switches. My PRTG is setup to collect SNMP data from Cyberoam and Cisco, all connections are up and PRTG is doing a great job. Don't know why, for every 10 to 15 minutes most of the sensors triggers warning No response (check: firewalls, routing, snmp settings of device, IPs, SNMP version, community, passwords etc) , they comes back to normal state after a minute or two. Some times port 30 triggers warning some times its 20. Can some one help me know if there are any bugs or configuration guidelines to solve this issue.

Thanks.

Article Comments

Hi,

what scanning interval are you using? Ping sensor on the devices constantly works and shows no errors/drops?


Dec, 2015 - Permalink

I am using 30 sec interval, there are few ping sensor drops too.


Dec, 2015 - Permalink

please try with longer intervals.

Could be possible that your devices actively block the traffic after some time due to flood protection.

Check the logs on your devices and check if they do have some sort of flood protection.

Some devices also do not update their SNMP counters that often so that a 30sec interval makes no sense anyways.


Dec, 2015 - Permalink

Thanks for your responses, a very valuable information. I figured the root cause for this issue, it was due to multiple Ethernet cards for my host system and both connected to different VLANs. When I disabled the unwanted Ethernet, the warnings went off. Is there an option to divert all PRTG traffic to a perticular Ethernet port?


Dec, 2015 - Permalink

Hello,

on the PRTG server itself, please start the PRTG Administration Tool from the PRTG program group.

On the tab "Probe Settings for Monitoring" you can select the NIC that the PRTG Probe should use for its monitoring.

The default is "auto", so you might want to change that to the desired NIC.

A restart of the probe service will be required.


Dec, 2015 - Permalink