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A user reports that they are being blocked from a website with a "Certificate Error." Which log will help the analyst determine if the firewall is blocking the session because the web server is using an expired certificate?
Comprehensive and Detailed 150 to 250 words of Explanation From Palo Alto Networks Network Security Analyst Knowledge:
When a firewall is performing SSL/TLS decryption, it acts as a proxy for the encrypted connection. If the firewall encounters an issue with the destination server's certificate---such as an expiration, an untrusted issuer, or a mismatch---the Decryption Log is the specific resource for troubleshooting.
The Decryption Log provides detailed information about why a decrypted session was failed or blocked. It explicitly lists the 'Error' or 'Reason' for the failure, such as expired-certificate or untrusted-issuer. While the Traffic Log (Option A) might show a 'deny' or 'reset' action, it will not provide the specific certificate details. By checking the Decryption Log, the analyst can confirm if the issue is a security problem with the external site or if the firewall's decryption profile needs to be adjusted to allow the connection (e.g., if it is a trusted internal site with a self-signed certificate).