Which of the following descriptions about the Portal authentication process is correct? (Multiple choice)

Question

Options

• AWhen using the Portal authentication protocol, if there is a NAT scenario between the
• BAfter receiving the Portal authentication request (REQ_AUTH), the Portal server will send a
• CThere are two ways to trigger Portal authentication, one is active authentication and the other is
• DWhen using the HTTP/HTTPS authentication protocol, if there is a NAT scenario between the

• A
  77% (17)
• D
  23% (5)

Explanation

Options A, B, and C are all accurate descriptions of Portal authentication behavior. Option A correctly describes how NAT scenarios are handled within the Portal authentication protocol - the access device (NAS) accounts for NAT by including the relevant IP information so the Portal server can properly identify the user. Option B accurately reflects the Portal protocol message exchange: upon receiving a REQ_AUTH request, the Portal server takes a defined next step (such as forwarding credentials to a RADIUS server or sending a challenge), which is part of the standardized Portal handshake. Option C is correct because Portal authentication is indeed triggered two ways - active (the user navigates to the portal page voluntarily) and forced/passive (the user is redirected when attempting any HTTP access while unauthenticated).

Option D is the distractor. It mirrors the phrasing of Option A but applies it to HTTP/HTTPS authentication - the claim it makes about NAT behavior in that context is incorrect or overstated, as HTTP/HTTPS-based portal pages do not handle NAT at the protocol layer the same way the Portal protocol does; HTTP redirects rely on the browser and do not carry the same IP-mapping mechanism.

Memory tip: Think of Portal auth as a three-legged stool - (1) two trigger modes (active/forced), (2) a defined message flow (REQ_AUTH → server response), and (3) NAT-awareness built into the Portal protocol itself. If an answer blurs the Portal protocol's NAT handling with generic HTTP/HTTPS behavior, it's likely the trap option.

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