DSSSB TGT CS 2023 Shift 2 – Question 169

Match the column Well-known ports used by TCP with the column Protocol.

• a-ii, b-i, c-iv, d-iii
• a-i, b-ii, c-iv, d-iii
• a-ii, b-iii, c-iv, d-i
• a-iii, b-i, c-iv, d-ii

According to IANA well-known port number assignments for standard TCP services:
– Port 7: Echo Protocol (RFC 862) – sends back any data received from the client (a \(\rightarrow\) ii).
– Port 9: Discard Protocol (RFC 863) – discards any data received without sending a response (b \(\rightarrow\) iii).
– Port 11: Active Users / SYSTAT (RFC 866) – provides a list of currently active system users (c \(\rightarrow\) iv).
– Port 13: Daytime Protocol (RFC 867) – returns the current date and time as human-readable ASCII text (d \(\rightarrow\) i).

Therefore, the matching is a-ii, b-iii, c-iv, d-i. The correct option is c).