The solution is derived by applying the company's system hardening guidelines to the discovered services on each device.

1. Primary Role Identification: Each device's role is determined by identifying its most significant service, aligning with the "one primary service per device" rule. For instance, a device running HTTP/HTTPS is a Web Server, and one running SMTP/IMAP is a Mail Server.
2. Disabling Non-Secure Protocols: The guidelines require disabling non-secure protocols. The analysis identifies services like Telnet, FTP, HTTP, and IMAP because they transmit data, including credentials, in cleartext. Protocols like NetBIOS and RPC are also identified as non-compliant due to well-known vulnerabilities. Their secure alternatives (e.g., SSH, SFTP, HTTPS, IMAPS) are compliant.
3. DMZ Placement: The device LunchTimeMike.Local is correctly placed in the DMZ, satisfying the requirement for protecting the corporate internet presence.

National Institute of Standards and Technology (NIST) Special Publication 800-123, Guide to General Server Security. Section 4.4, "Services," advises to "disable services that are not required." It emphasizes minimizing the attack surface by removing or disabling all unnecessary functions and services.

Kurose, J. F., & Ross, K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Chapter 8, "Security in Computer Networks," details the vulnerabilities of protocols like Telnet and FTP, which transmit passwords and data in the clear, contrasting them with secure protocols like SSH and SSL/TLS.

Internet Engineering Task Force (IETF) RFC 854, Telnet Protocol Specification. The specification for Telnet does not include provisions for encryption, making it fundamentally insecure for transmitting sensitive information over untrusted networks.

Internet Engineering Task Force (IETF) RFC 959, File Transfer Protocol. Section 4.1 describes the unencrypted transmission of commands and data, which is the basis for its classification as a non-secure protocol. Secure alternatives like FTPS (RFC 4217) or SFTP are recommended.