Zabbix server stopped monitoring after network interruption event

[vic]

Running the latest stable v2.4.x installed from RPM on CentOS v7

Yesterday my zabbix server was not reachable for about 30minutes because there was a DDoS on the datacenter. I was still getting outbound email alerts and everything.

After the event unbeknownst to me the server stopped monitoring remote servers for some reason. If I look at the graphs, there was no data being collected and all the servers basically showed as offline. I was not getting any email notifications about it although that may be because the triggers all remained tripped after the DDoS event. Also because I got a bunch of untripped notifications after the reboot.

Everything is monitored with remote zabbix-agents. I rebooted the zabbix-server and everything started working again. Is this a known issue by any chance? Maybe it was my network interface or something although I was able to connect to the web GUI and via SSH before I rebooted. So networking appeared to be working normally.

[LenR]

Could this have been in the window of "Refresh unsupported items"? If items go unsupported or servers loose contact, the polling is stopped and zabbix waits for this interval before trying again.

[vic]

Could this have been in the window of "Refresh unsupported items"? If items go unsupported or servers loose contact, the polling is stopped and zabbix waits for this interval before trying again.

What is the default interval? Where is that setting? It was not monitoring for 12hours. Basically from the time the incident occurred until I discovered it and rebooted...about 12 hours later. Almost as if zabbix-server stopped working. I should have tried more troubleshooting before rebooting but I just wanted to get it working again at the time.