When I restart the server, I lose connection. the vnics go into disconnect despite there being a cable connected to the port.
You mean the physical NICs in the host, that are used as the uplinks for your virtual switches?
What version of ESXi?
What system and NIC hardware?
You mean the physical NICs in the host, that are used as the uplinks for your virtual switches? yes
What version of ESXi? Lenovo Customized Image ESXi6.0 Update 3 (based on ESXi 6.0 Vmkernel Release Build 9313334)
What system and NIC hardware? LENOVO SR850 INTEL X722 LOM
Hi,
Maybe I'm wrong but from that I understand neither that controller nor the system as a whole are in HCL (or "supported" by the manufacturer) with ESXi version 6.0, also this no longer supported for some time now. Always if I'm not mistaken the minimum supported version was from ESXi version 6.5U2 and later.
Maybe consulting the LOGs of your host and of your network equipment could give you some more information and since it doesn't take long, check the network cables too, it is not so uncommon to find faulty ones. This has happened to me more than once regardless of "brand or cost".
Regards,
Ferdinando