A firewall technician has been instructed to disable all non-secure ports on a corporate firewall. The technician has blocked traffic on port 21, 69, 80, and 137-139. The technician has allowed…

This choice omits FTP (port 21) from the blocked list and incorrectly lists HTTPS as an allowed protocol while missing SSH, SFTP, and SCP that also travel over the allowed port 22.

Port 21 is the FTP control port, port 69 is TFTP, port 80 is HTTP, and ports 137-139 are used by NetBIOS for name resolution and session services - all of these are unencrypted or inherently insecure protocols that the technician blocked. Port 22 hosts SSH, which also provides the transport layer for SFTP and SCP, making all three protocols available when port 22 is open. Port 443 carries HTTPS, the encrypted version of web traffic, completing the list of allowed secure protocols.

This choice incorrectly lists SFTP as blocked rather than allowed, since SFTP operates over SSH on port 22 which was explicitly left open by the technician.

This choice incorrectly places HTTPS in the blocked category and NetBIOS in the allowed category, which is the opposite of what the port assignments indicate.