If after ESXi upgrade the host does not see network card. You need to check the compatibility of drivers which came with a new ESXi version with your network card firmware. This example is for Emulex HP NC550SFP (Part Number 581201-B21) and ESXi 6.0 U1b HP custom image.
- Check the current BIOS version for Emulex 10GB card (version 4.9.416.2)
2. Check VMware Compatability Guide for the specific network card (i.e. HP NC550SFP http://www.vmware.com/resources/compatibility/detail.php?deviceCategory=io&productid=17123)
3. SSH to host and check the firmware version installed: esxcli software vib list | grep elxnet
VMware ESXi 6.0 U1b comes with 10.5.121.7-OEM.600.0.0.2159203 driver for elxnet. This driver does not support the NC550SFP card’s firmware version. Need to downgrade the drivers.
4. Download the driver version required (10.2.298.5)
5. Remove the elxnet vib: esxcli software vib remove -n elxnet
6. Install the required driver version: esxcli software vib install -d “/vmfs/volumes/datastore/tmp/VMW-ESX-5.5.0-elxnet-10.2.298.5-offline_bundle-2263089.zip”
7. Reboot the host: esxcli system shutdown reboot -r ‘Downgrade Emulex HP NC550SFP driver (elxnet) to 10.2.298.5’
VMware kb2008939: Installing patches on an ESXi 5.x/6.x host from the command line (2008939)