Which port is used by the Ident service in another item?

Which port is used by the Ident service in another item?

• A. 25
• B. 110
• C. 113
• D. 5353

Answer: (C)

Ident uses TCP port 113. This protocol, described in RFC 1413, lets a machine ask the other end of a TCP connection who owns that connection by querying the peer’s Ident daemon on port 113. The response reveals the user associated with the connection, though this feature is largely legacy today due to privacy and security concerns. For context, other common services use different ports: port 25 is for SMTP email, port 110 is for POP3 email retrieval, and port 5353 is used by multicast DNS/service discovery.

Ident uses TCP port 113. This protocol, described in RFC 1413, lets a machine ask the other end of a TCP connection who owns that connection by querying the peer’s Ident daemon on port 113. The response reveals the user associated with the connection, though this feature is largely legacy today due to privacy and security concerns.

For context, other common services use different ports: port 25 is for SMTP email, port 110 is for POP3 email retrieval, and port 5353 is used by multicast DNS/service discovery.