Recently I have upgraded my Zabbix server from 2.2 to 3.0 version and also all my servers are running Zabbix agents with version 3.0.x.
After the server upgrade, I started to receive messages like IP packet loss or DNS resolution failed daily.
Recap:
1. messages often come during night, rarely during a day 06:00 - 18:00,
2. they don't come from all our servers, just from couple of them - they are in different VLANs,
3. I already checked correlation between nightly backup jobs and these messages and there's none,
4. CPU and network utilization of Zabbix server and agents is low,
5. time between PROBLEM and OK messages is usually 1 minute, at most 10 minutes,
6. I have checked our other monitoring tools and I cannot see any problem with our internet connection (especially during night).
7. our servers use 8.8.8.8 or 8.8.4.4 or both for DNS servers IPs.
After the server upgrade, I started to receive messages like IP packet loss or DNS resolution failed daily.
Recap:
1. messages often come during night, rarely during a day 06:00 - 18:00,
2. they don't come from all our servers, just from couple of them - they are in different VLANs,
3. I already checked correlation between nightly backup jobs and these messages and there's none,
4. CPU and network utilization of Zabbix server and agents is low,
5. time between PROBLEM and OK messages is usually 1 minute, at most 10 minutes,
6. I have checked our other monitoring tools and I cannot see any problem with our internet connection (especially during night).
7. our servers use 8.8.8.8 or 8.8.4.4 or both for DNS servers IPs.