Devices losing sysname when offline makes device not in a group anymore

I’m using the option “force_ip_to_sysname” in my config to make finding devices more friendly which is a pretty nice feature. However it seems like sometimes when a device is down for a while it will lose its sysname which actually will break it out of a group if it is in one (I’m using some static groups). Any idea what could be causing this? It is creating an issue during maintenance because devices are still alerting when they should not be because they are not in a group that is set for maintenance. I’m wondering if maybe the device was being polled via smnp and maybe went down during the poll causing the sysname to become invalid, that’s really the only thing I can think of.


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PHP 7.3.10
Python 3.6.8
MySQL 5.5.64-MariaDB
RRDTool 1.7.1


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I have the same problem.

Yeah it would be great if we could just know why this was happening but I have no idea at this point.

A device being offline won’t cause it to lose sysName. The snmp service on the device dying mid-poll could be one possible reason.

You can have static device groups.

Using hostname will be 100% stable.