Here are two quick ways to check the driver version of a network interface card. The commands must be executed in the ESX COS or ESX(i) Tech Support Mode.
vmkload_mod is a tool to manage VMkernel modules. It can be used to load and unload modules, list the loaded modules and get the general information and available parameters of each module.
~ # vmkload_mod -s bnx2x | grep Version Version: Version 1.54.1.v41.1-1vmw, Build: 260247, Interface: ddi_9_1 Built on: May 18 2010 ~ #
ethtool is a Linux command line tool that allow us to retrieve and modify the parameters of an ethernet device. It is present in the vast majority of Linux systems, including the ESX Service Console. Fortunately for us VMware has also included it within the busybox environment of the ESXi.
~ # ethtool -i vmnic0 driver: bnx2x version: 1.54.1.v41.1-1vmw firmware-version: BC:5.2.7 PHY:baa0:0105 bus-info: 0000:02:00.0 ~ #