ESXi 6.7 always loses connection.

[SommyJo]

 I have a Dell T420 server with ESXi 6.7.
In this there are VMs with shared folders. There are only 5 users connecting to these folders.
They have been complaining for days that they are losing connections. Today I also lose the connection to the management address, the one that appears on the server screen.

In the server there is also a VM with RealVNC, so that I can connect remotely and from there manage the configuration panel and sometimes even this is unreachable.

I have turned servers, switches, PCs, routers, etc. on and off several times.

At this point I am wondering if it is not a problem with the server itself, although all the LEDs of all the NICs are blinking correctly.

How can I diagnose this?

Thanks in advance

[e_espinel]

Hello.

What level (Build) of ESXi 6.7 do you have ?

it may be necessary to update your level, in general you should update the levels (patches) and firmware levels (Hardware) periodically as part of the maintenance plan of the equipment.

What brand and model of ethernet card do you have in the sErver?

I don't see in Dell or VMware that the Dell T420 server is supported for version 6.7 according to the attached links it is only supported up to version 6.5.

https://www.dell.com/support/manuals/en-us/vmware-esxi-6.5.x/esxi6.5.x_vsphere_compmatrix_pub/dell-e...

https://www.dell.com/support/manuals/en-us/vmware-esxi-6.7.x/esxi_6.7_vsphere_compmatrix_pub/dell-em...

https://www.vmware.com/resources/compatibility/detail.php?deviceCategory=server&productid=19272

[SommyJo]

The build is 8169922.

I didn't remember ever upgrading to 6.7, in fact I was convinced I had 6.5. However if the update has been done it must be before 2019.

Until yesterday it has always worked, it hasn't accepted the connection to the management IP since last night.

Today I noticed an error message at boot, immediately before the last boot screen, the one with the IP; it was a flash, less than a second.

However, I managed to capture it in a frame of a video, but it looks very bad and I'm not sure I'm reporting the message correctly.

cpu1 [2097xx8] Failed to verify signature of the following xxxxxx. All hardlinks validated.
cpu0 [2099335] Expected (partner) found vlbs with (community) acceptance level

[e_espinel]

Hello.
The build 8169922 is the initial base of version 6.7 ( GA 2018), it's like having a Windows without any patch.
As your Dell server model is not supported for version 6.7 you will have to be cautious. You could upgrade to 6.7 Update 1 (Build 10302608) and check how ESXi behaves.
If your problems are very recurrent and critical you should seriously think about going back to version 6.5 Update 3 which is the supported version, and install the latest patches.

Attached is a link where to get the patches:

https://my.vmware.com/group/vmware/patch#search

It is always recommended to perform a full backup of the data before any upgrade or work that involves changes.

It is also important to update the server firmware, especially the network card firmware.