The Challenge Handshake Authentication Protocol (CHAP) is used with iSCSI on an
ESX Server to provide which of the following?

A.
Bi-directional Target authentication

B.
Initiator authentication

C.
LUN Group authentication

D.
Storage Processor authentication

Explanation:
iSCSI SAN Configuration Guide ESX 4.0 ESXi 4.0 vCenter Server 4.0, page 37.
Because the IP networks that the iSCSI technology uses to connect to remote targets do
not protect the data they transport, you must ensure security of the connection. iSCSI
requires that all devices on the network implement Challenge Handshake Authentication
Protocol (CHAP), which verifies the legitimacy of initiators that access targets on the
network.