After upgrade of ESXi 5.5 to 6.0 server loses every few days the network connection

[xiadm]

The upgrade went smoothly, just days later the server lost the network connection. Only way to get back the network is a hard reboot.

This issue was repeated several times now. The Server had two Intel 82574L NIC's.

Last time of connection loss, today 2015-08-11T08:00:01Z. ESXi Build: 2809209

[DSchef]

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.

[DSchef]

See a larger thread of the issue I described at https://communities.vmware.com/message/2525461?tstart=0#2525461

[xiadm]

Thanks for your answer. Today the problem occurred again. Now I go back to 5.5 and hope that a patch appears soon.

[Q3Q]

Hi guys

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...

[cesprov]

See here for a workaround script.

[Q3Q]

in my case it was the e1000e driver on the host.

this seems to have been resolved wit 6.0u1

VMware vSphere 6.0 Updated 1 Release Notes

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

[rseabrooke]

ESXi 6.0 network connectivity is lost with NETDEV WATCHDOG timeouts in the vmkernel.log (2124669)

[sarikrizvi]

Try to Apply this KB -1005757 VMware Knowledge Base

Monitor host disconnection for few days and it will help .