Unity 400 using iSCSI with 2 switches - IP subneting

all,

we have a unity 400 that is currently only connected to 1 hosts using iscsi and one switch.

we are looking to expand this an add a second network switch for redundancy and also connect additional ports for iSCSI.

I am used to MD and SC storage where 2 or more "fault domains" were configured and each fault domain had a different IP subnet... is this the same configuration\setting with the Unity 400?

the documentation shows a very basic diagram for iscsi and does not included really any info for iscsi with dual switches and multiple hosts.

any info would be appreciated

thanks