Special considerations apply to network adapters, both physical and VMkernel, that are associated with an iSCSI adapter.
After you create network connections for iSCSI, an iSCSI indicator becomes enabled in the vSphere Web Client. The indicator shows that a particular virtual or physical network adapter is iSCSI-bound. To avoid disruptions in iSCSI traffic, follow these guidelines and considerations when managing iSCSI-bound virtual and physical network adapters:
Make sure that the VMkernel network adapters are assigned addresses on the same subnet as the iSCSI storage portal they connect to.
iSCSI adapters using VMkernel adapters cannot connect to iSCSI ports on different subnets, even if the iSCSI adapters discover those ports.
When using separate vSphere switches to connect physical network adapters and VMkernel adapters, make sure that the vSphere switches connect to different IP subnets.
If VMkernel adapters are on the same subnet, they must connect to a single vSwitch.
If you migrate VMkernel adapters to a different vSphere switch, move associated physical adapters.
Do not make configuration changes to iSCSI-bound VMkernel adapters or physical network adapters.
Do not make changes that might break association of VMkernel adapters and physical network adapters. You can break the association if you remove one of the adapters or the vSphere switch that connects them. Or if change the 1:1 network policy for their connection.