If you use the software iSCSI adapter or dependent hardware iSCSI adapters, you must set up the networking for iSCSI before you can enable and configure your iSCSI adapters. Networking configuration for iSCSI involves opening a VMkernel iSCSI port for the traffic between the iSCSI adapter and the physical NIC.

Depending on the number of physical NICs you use for iSCSI traffic, the networking setup can be different.

If you have a single physical NIC, create one iSCSI port on a vSwitch connected to the NIC. VMware recommends that you designate a separate network adapter for iSCSI. Do not use iSCSI on 100Mbps or slower adapters.

If you have two or more physical NICs for iSCSI, create a separate iSCSI port for each physical NIC and use the NICs for iSCSI multipathing. See Networking with iSCSI.

Networking with iSCSI
Networking with iSCSI.

When you use a dependent hardware iSCSI adapter, performance reporting for a NIC associated with the adapter might show little or no activity, even when iSCSI traffic is heavy. This behavior occurs because the iSCSI traffic bypasses the regular networking stack.