Exam ZDTE Topic 1 Question 15 Discussion

In a Zscaler Private Access (ZPA) deployment, traffic from users to Active Directory Domain Controllers and SCCM servers is proxied through App Connectors. ZPA performs DNS proxy and source NAT (SNAT) on these connections, which means the Domain Controller often sees the App Connector's IP address-rather than the end user's-when deciding which AD Site the "client" belongs to.
Zscaler's Active Directory integration guidance explains that AD site selection is therefore based on the App Connector IP, and recommends adding those connector IPs into the appropriate Active Directory Sites and Services configuration. Doing so ensures that when authentication, Group Policy, DFS, or SCCM traffic arrives via ZPA, the Domain Controller or SCCM infrastructure maps the connection to the correct site and routes users to the nearest or most appropriate DC/SCCM server, preserving efficient logon performance and content distribution.
This configuration has nothing to do with BGP routing design (option A), direct admin access to DCs by IP (option B), or the basic ability of ZPA to use AD for identity (option C). ZPA can integrate with AD without Sites and Services, but optimizing which DC/SCCM server is used depends on having App Connector IPs correctly associated with AD Sites. Thus, the correct reason is that it ensures users connect to the closest Domain Controllers or SCCM servers.