Server stops talking to SNMP devices

[ebonweaver]

In the wee hours of the night the server suddenly stopped talking to 4 printers at the same time for no apparent reason. It claims they are unreachable by SNMP, but they are fine. We also know nothing changed on it's own simultaneously on 4 devices out of all those monitored. I can find no obvious way to kick the server into talking properly to these devices again.
Any advice is appreciated.

[Atsushi]

What version are using of Zabbix?

If you're using a 2.2.7 or later, please try to set the EnableSNMPBulkRequests to 0 in zabbix_server.conf.
If it is 2.4, please remove check for Use bulk requests of the SNMP interface of the target host.

[ebonweaver]

Nevermind, turned out to be due to a sad comedy of network and device configuration issues. *sigh*

[LenR]

That is the most popular cause for most of us.....