The Nmap command uses the Xmas scan technique, which sends packets with the FIN, PSH, and URG flags set. This is an attempt to bypass firewall rules and elicit a response from open ports. However, if the target responds with an RST packet, it means that the port is closed. Open ports will either ignore the Xmas scan packets or send back an ACK packet. Therefore, the information most likely indicates that all of the ports in the target range are closed. References: [Nmap Scan Types], [Nmap Port Scanning Techniques], [CompTIA PenTest+ Study Guide: Exam PT0-002, Chapter 4: Conducting Passive Reconnaissance, page 127]