An enterprise deployment of Prisma Access uses explicit proxy. Users report that authentication prompts appear repeatedly when browsing internal web applications. What is the most likely cause of this authentication looping in an explicit proxy setup?
Explicit proxy authentication loops occur when the proxy intercepts the identity provider's own login traffic, so credentials are never cached. Bypassing those login pages and correcting cookie persistence in the explicit proxy profile restores the authentication flow, satisfying the stem's repeated-prompt symptom.
Why this answer
In an explicit proxy deployment, authentication looping typically occurs when the proxy intercepts the identity provider's login pages or when cookie persistence is misconfigured, causing the proxy to challenge the user repeatedly instead of honoring the authentication cookie. Adding proxy bypass entries for authentication provider URLs and correcting cookie persistence settings in the explicit proxy profile resolves the loop.
Exam trap
SSE-Engineer often tests explicit proxy authentication mechanics, so the trap is attributing repeated login prompts to tunnel or routing issues rather than to proxy bypass and cookie persistence configuration.
How to eliminate wrong answers
Option A is wrong because BGP hold timers govern routing adjacency stability on the Service Connection, not user authentication behavior through an explicit proxy. Option C is wrong because SSL Forward Proxy decryption being disabled would prevent inspection of encrypted traffic, but it would not cause repeated authentication prompts — it would simply leave traffic uninspected. Option D is wrong because GlobalProtect agent version compatibility is irrelevant to explicit proxy authentication; explicit proxy clients are browsers or PAC-configured endpoints, not necessarily GlobalProtect agents.