To integrate Cisco Identity Services Engine (ISE) with Active Directory (AD), the ISE node must join the AD domain. This enables Cisco ISE to authenticate users and devices against the directory and enforce policies based on AD attributes. Steps to Perform the Join Operation: 1. Navigate to Administration > Identity Management > External Identity Sources > Active Directory in the Cisco ISE GUI. 2. Provide the AD domain name and ensure network connectivity to the AD servers. 3. Use an AD account with appropriate privileges (often a domain admin or delegated account with join permissions) to perform the join operation. 4. After successful domain join, Cisco ISE can query the AD for user and group information.