VMkernel network interfaces are used primarily for management traffic, which can include vMotion, IP Storage, and other management traffic on the ESXi system. You can also bind a newly created VMkernel network interface for use by software and dependent hardware iSCSI by using the esxcli iscsi commands.

The VMkernel network interface is separate from the virtual machine network. The guest operating system and application programs communicate with a VMkernel network interface through a commonly available device driver or a VMware device driver optimized for the virtual environment. In either case, communication in the guest operating system occurs as it would with a physical device. Virtual machines can also communicate with a VMkernel network interface if both use the same virtual switch.

Each VMkernel network interface has its own MAC address and one or more IP addresses, and responds to the standard Ethernet protocol as would a physical NIC. The VMkernel network interface is created with TCP Segmentation Offload (TSO) enabled.

You can manage VMkernel NICs with ESXCLI and with vicfg-vmknic.