Intermittent Data from Cisco Switches via SNMPv2

[popcomputer]

Hi everyone,

I've recently started using Zabbix 7.0 to monitor network devices at my workplace.
I'm trying to monitor multiple Cisco switches via SNMPv2, including the following models:

• Cisco Catalyst 9500
• Cisco Catalyst 2960X
• Cisco SG300-500
• Cisco CBS250

There are 55 hosts in total.

I configured each host in Zabbix using the "Cisco IOS by SNMP" template. Zabbix is able to connect and retrieve data from all devices successfully.

However, after running for some time, the data from all hosts becomes intermittent — it appears and disappears randomly, as shown in the screenshot below.

I have already tried adjusting several parameters in zabbix_server.conf, including:

CacheSize=8G
StartPollers=100
StartSNMPPollers=100
StartPingers=100​

I also tested by reducing the number of monitored hosts to only one (tested with all switch models), but the issue still persists.

Has anyone experienced a similar problem or have any ideas on how to resolve it?

Environment:
Zabbix 7.0
Ubuntu 24 Server (VMware installation)

Thanks in advance for any suggestions or insights.