Which protocol is expected to have NTP a user agent, host, and referrer headers in a packet capture?

NTP (Network Time Protocol) is used for time synchronization and transmits binary timestamp data using its own packet format - it does not use HTTP-style headers.

HTTP request messages include standardized headers such as User-Agent (identifying the client software), Host (specifying the target server), and Referer (indicating the originating page). These are defined in RFC 7231 and are transmitted as plaintext in HTTP/1.1, making them readily visible in a packet capture. No other protocol in this question uses this header format.

DNS uses a binary query and response format with its own record types (A, AAAA, MX, etc.) and does not include headers like User-Agent or Referer.

SSH creates an encrypted channel for secure remote access and does not transmit HTTP-style headers - its protocol uses binary framing with key exchange and encryption negotiation.