Devices randomly stops pinging

[soamz]

What would be the reason, devices randomly stops pinging from server and nagios ?

You can see my screenshot, 3 devcies show red.
Its showing red since yesterday. But the devices are online and its being used by the users too
But when I restart the device, the nagios tells its green.
What would be the reason ?

[Box293]

Perhaps there is another machine in the same subnet with the same IP address as the Nagios Core server.

Are your other servers in the same subnet as Nagios XI? If not the firewall/router they traverse may be rate-limiting the connections.

[soamz]

Perhaps there is another machine in the same subnet with the same IP address as the Nagios Core server.

Are your other servers in the same subnet as Nagios XI? If not the firewall/router they traverse may be rate-limiting the connections.

No there is no duplicates.
arp -a shows only one entry for each IP.

[rhassing]

Is only the nagios server not able to ping these devices?
Can other hosts ping these devices?

Could it be a firewall on the devices?

[rkennedy]

This sounds like a networking issue that isn't related to Nagios.

Do you hava rate limiting, ICMP flood prevention, or a firewall / antivirus in play? All of these can stop 'ping' checks from working.