VMkernel Network Interfaces

The network services that the VMkernel provides (iSCSI, NFS, and VMotion) use a TCP/IP stack in the VMkernel. This stack accesses various networks by attaching to one or more port groups on one or more virtual switches.

The VMware VMkernel TCP/IP networking stack handles iSCSI, NFS, and VMotion in the following ways.

• iSCSI as a virtual machine datastore
• iSCSI for the direct mounting of ISO files, which are presented as CD-ROMs to virtual machines
• NFS as a virtual machine datastore
• NFS for the direct mounting of ISO files, which are presented as CD-ROMs to virtual machines
• Migration with VMotion

If you have two or more physical NICs for iSCSI, you can create multiple paths for the software iSCSI by using port binding. For more information on port binding, see the iSCSI SAN Configuration Guide.

A freshly installed ESX/ESXi system does not include VMkernel network interfaces. When you wish to migrate a virtual machine with VMotion, your VMkernel networking stack must be set up properly. When you want to use storage types that use TCP/IP network communications, such as iSCSI, you must provide a separate VMkernel network interface for that storage device. You must create any VMkernel ports you might need (see Adding a VMkernel Network Interface).