So what you are saying is that all machines being monitored by the Nagios 4.0.8 VM, which is now running on a KVM host, do not work with remote NSClient++ agents.scottthepotter wrote:I was recently running Nagios 4.08 on a CentOS 6.6 VM under VirtualBox monitoring Windows servers using NSClient ++ and all was fine. I have moved the VM to a KVM host, maintaining the same MAC Address and IP address and now I am receiving 'No data received from host' from all other guest machines on the same host as the nagios guest. I am able to ping both ways from guest to guest. SELINUX is disabled. Since network traffic on QEMU bridged machines does not get intercepted by the host, I can't imagine that it would be a firewall rule. Where to start?
Pings work OK. From core to guest and guest to core.
This does sound like a KVM networking issue. I've not played with KVM but I can offer some troubleshooting suggestions.
What you could try is to remove the existing VM network card in the Core box and add it again with a new MAC address. Then reconfigure it with it's OLD IP Address.
My gut feeling is that bdgoecke is on the right track.
Another troubleshooting step is to quickly run up another Core VM and do some networking tests from it to the Windows hosts. Save yourself time and use a Nagios XI VM which has Core and all the plugins installed. I'm sure KVM allows you to import an OVA.
When I get stuck with issues like this I like to draw a line in the sand. Is it the VM? If the same problem occurs in another VM then it's not the VM's problem but perhaps KVM.