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Sensors fail after internet outage



The internet connection of the monitored machines is fine, the systems are OK without problems. I have at my office a local PRTG server.

If my local PRTG server losses the internet connection, the sensors state becomes down. When the internet connection returns the sensors are still down forever.

The only way to fix this issue is restarting the SNMPD at the remote machines.

How can avoid this problems? Thanks.

internet-loss problem snmp

Created on Feb 27, 2018 9:56:38 AM

3 Replies



What kind of sensors and devices are these? Is this possibly a DNS issue for PRTG not able to reach them after the internet connectivity is restored?

Created on Feb 28, 2018 3:21:19 AM by  Benjamin Day [Paessler Support] (1,441) 2 1



Yes. You're right. I'm using SNMP. The monitored (remote) machines, have static IP but here at the office where is located the PRTG Core Server I have dynamic public IP that relay in a Dyn DNS domain. The SNMP community is configured to only allow requests from my DDNS domain. It think that this is the real problem. When I have Internet outage at my office (PRTG server side) my ISP renews my IP and the DDNS software updates the DNS with the new IP but for some reason, the remote monitored machines don't allow the access under this scenario until I restart the SNMP daemon.

How can I do to avoid this strange behavior?? I'm thinking to use a unrestricted SNMP rocommunity with a complex community string (to improve secutiry instead the host restriction). What do you think about this workaround? I'm right?

Thank you a lot.

Created on Feb 28, 2018 7:49:35 AM



Can you give me an overview of this network logically? I'm having a hard time visualizing what you're trying to make work here.

Created on Feb 28, 2018 6:19:56 PM by  Benjamin Day [Paessler Support] (1,441) 2 1

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