GoodEvening.
I'm experiencing a problem I hope you can help me to figure out.
I have a six nodes vSphere 5.1 cluster.
All of a sudden, randomly some VMs started experiencing network connectivity loss.
Often, if I open the VM settings I find the "Connected" check of the NIC configuration incredibly unchecked.
If I check the setting and I close and reopen the "edit setting" window. I find it unchecked again.
Other times, the VM results unreachable from the network even if the setting is correctly checked.
All I have to do to have the VM back on the network is to perform a vMotion.
I vMotion the machine and everything starts working fine again.
Is not a problem of an host I think, however.
The problem happens on any host, and if I vMotion a VM off of the host where it was experiencing this problems and after i vMotion it back on the same host, the VM works fine.
Anyway, I rebooted all the hosts of this cluster
I don't think it's a vNIC problem, since I have already tried to switch between vmxnet3 and e1000 and vice versa.
Also the problem happens on different machines with both the interfaces.
I have only windows VMs, but I don't think it could be Windows.
I have VMs running from Win2003 to Win2012R2, even some client OS such Windows7, and the problem happens on any of them.
The vSwitch are standard, using 4 physical load balanced NIC for uplink.
Load balancing: Route based on the originating virtual port ID
Network failover detection: Link status only
Notify switch: yes
Failback: yes
All the links are in trunk mode.
All the portgroups are configured the same on any host with the correct VLANID.
Have you please any idea of what I'm missing?
Thank you for your kind help.
