A network administrator can transparently identify users using Active Directory on the Cisco WSA in two ways:

Create NTLM or Kerberos authentication realm and enable transparent user identification. This option allows the WSA to use the NTLM or Kerberos protocol to authenticate users without prompting them for credentials. The WSA must join the Active Directory domain and have a valid service principal name (SPN) for this option to work1.

Deploy a separate Active Directory agent such as Cisco Context Directory Agent (CDA). This option allows the WSA to receive user-to-IP mappings from the CDA, which monitors the Active Directory domain controllers for user logon events. The CDA must be installed on a Windows server and have access to the domain controllers and the WSA2.

The other options are not ways to transparently identify users using Active Directory on the Cisco WSA. Creating an LDAP authentication realm and disabling transparent user identification will require users to enter their credentials manually. Installing the eDirectory client on each client workstation or deploying a separate eDirectory server are not related to Active Directory, but to Novell eDirectory, which is a different directory service3.

References := 1: User Guide for AsyncOS 11.0 for Cisco Web Security Appliances, Chapter: Acquire End-User Credentials, Topic: Active Directory/Kerberos, page 4-3. 2: User Guide for AsyncOS 11.0 for Cisco Web Security Appliances, Chapter: Acquire End-User Credentials, Topic: Active Directory Agent, page 4-5. 3: User Guide for AsyncOS 11.0 for Cisco Web Security Appliances, Chapter: Acquire End-User Credentials, Topic: eDirectory, page 4-8.