Reach out to VMware support on this issue to see if it is related to a known bug in ESXi 6. The event logged in my experience with this same situation is "netdev_watchdog:3678: NETDEV WATCHDOG". I did not see this in your logs but the failure scenario I have experienced is the same as you described.
I ran into a similar situation that VMware acknowledged as a bug in 6.0 about a month ago. The only workaround is to downgrade hosts back to 5.5 until an update is available. VMware engineering has been working on a fix but progress has been slow. VMware support and management are very silent on this one.
Thanks for your answer. Today the problem occurred again. Now I go back to 5.5 and hope that a patch appears soon.
I'm seeing the same thing.
One thing we all seem to have in common ist the presence of Intel 82574L NIC's.
My system worked perfectly for several year until the upgrade to 6.0.
So to me it seems quite clear that this has something to do with the network drivers of 6.0 for Intel 82574L NIC's.
Maybe I should try to downgrade the VIB for these NICs...
Unfortunately my server is no longer officially supported by VMware so opening a support ticket won't help much...
in my case it was the e1000e driver on the host.
this seems to have been resolved wit 6.0u1
An ESXi host might lose connectivity and e1000e virtual NIC might get reset
An ESXi host might intermittently lose connectivity and e1000e virtual NIC might get reset. An All Paths Down (APD) condition to NFS volumes might also be observed. An error message similar to the following is written to the vmkernel.log file
packets completion seems stuck, issuing reset
This issue is resolved in this release.
You can check if this might be the case if you enter this in the command line of your server:
esxcli network nic list
If a driver is listed as «e1000e» then you could try updating to 6.0U1
ESXi 6.0 network connectivity is lost with NETDEV WATCHDOG timeouts in the vmkernel.log (2124669)