Which port number is associated with the Discard service?

Which port number is associated with the Discard service?

• A. 13
• B. 19
• C. 135
• D. 9

Answer: (D)

The Discard service is a simple protocol whose purpose is to receive data and throw it away without sending any response. It is standardized to listen on UDP port 9, which is why this port is the correct one for Discard. The other ports correspond to different well-known services: port 13 is Daytime (returns the current date/time), port 19 is CHARGEN (Character Generator), and port 135 is used by the RPC Endpoint Mapper in Windows networking. So, port 9 is the correct association for the Discard service.

The Discard service is a simple protocol whose purpose is to receive data and throw it away without sending any response. It is standardized to listen on UDP port 9, which is why this port is the correct one for Discard. The other ports correspond to different well-known services: port 13 is Daytime (returns the current date/time), port 19 is CHARGEN (Character Generator), and port 135 is used by the RPC Endpoint Mapper in Windows networking. So, port 9 is the correct association for the Discard service.