Hi jcp2mill,
If your network connectivity is untagged so you are transfer all vlans as Trunk .
You need to create the vmkernel of the ISCSI with the vlan_id of the network.
Please provide more details on your network topology .
4 Physical NICs , each nic connected to a switch ?
the port on the switch is access or trunk ?
what is the vlan of the ISCSI ?
how many vSwitchs you created on your ESXi and which vmnic used as uplink ?
Avi.