We use a HA-cluster with 2 ESXi, 6.0.0, 6921384 .
"Suddenly" on 2018-08-03 more and more network-devices started not getting contact to the network again after disconnect. I found out that our radius-server wasn't reachable any more on the ESXi (I call it Nr1) it is guest on. The radius-sever is a Debian GNU/Linux 5 (64-bit), no VMWare-tools installed.
From one day to the next it wasn't reachable any more. One thing could be importand: a few days before, on 2018-07-25 my colleague checked for updates, maybe installed some. I'm not sure where to find it out.
Long story short. Nobody is aware to have changed anything in the physical- or VM-network. I checked everything including the network-configuration of the radius. Other machines on the same ESXi (Nr1) seemed to be not effected, but not sure - I only recognized problems with the radius-server.
Another effect: other machines on the other ESXi (Nr2) in the HA-cluster wasn't able to reach the radius-server too... But other machines on the ESXi.
After a long way I asked myselfe what would happen if I move the radius on ESXi (Nr2)..? I did and found out that now everything works normal again.
The actual situation is that I moved all machines to the ESXi (Nr2) because now everithing works ok. I can't find problems with ESXi (Nr1), the config seems to be all the same as ESXi (Nr2). I'm not sure if HA would work too. But if it would, I would have the problem of not reach the radius.
Any idea what to try or how to solve it..?