This document demonstrates how to configure iSCSI bidirectional CHAP between ESXi 5.1 Update 1 and NetApp storage. There were to many screen captures for a regular post so I created the pdf below.

Versions in use for this document:
1) VMware vSphere vCenter 5.1 Update 1c Web Client
2) VMware ESXi 5.1 Update 1
a. Note: The ESXi software iSCSI initiator will be used for this document
3) NetApp Data ONTAP 7.3.7P3 (this also works with Data ONTAP version 8x)

The HOWTO is here: Bidirectional CHAP with vSphere 5.1u1c.pdf