Refer to the exhibit. An engineer is designing a guest portal on Cisco ISE using the default configuration. During the testing phase, the engineer receives a warning when displaying the guest portal.

An expired certificate would typically result in a browser warning explicitly stating that the certificate is expired, rather than a general warning about an untrusted site as commonly seen with default ISE deployments.

Cisco ISE, by default, generates self-signed certificates for its portal services when initially deployed or not integrated with a trusted Certificate Authority (CA). Web browsers do not inherently trust self-signed certificates, leading to security warnings to alert users about the unverified identity of the website.

A connection using an unsupported protocol would typically manifest as a connection failure or a distinct protocol error message, not primarily as a security warning related to certificate trust.

An unsupported browser would usually display a browser compatibility message or render the page incorrectly, rather than generating a security warning specifically about the site's certificate.