Which protocol is tightly linked with IP and is usually written as TCP/IP?

Which protocol is tightly linked with IP and is usually written as TCP/IP?

• A. UDP
• B. ICMP
• C. IGMP
• D. TCP

Answer: (D)

IP handles addressing and routing but doesn’t guarantee delivery or order. TCP sits on top of IP to provide reliable, connection-oriented transport with sequencing, error checking, and flow control. Because they work together to enable dependable end-to-end communication, the combination is ubiquitously written as TCP/IP. The other protocols—UDP, ICMP, and IGMP—are part of the IP suite but serve different roles (UDP is another transport option without reliability guarantees, ICMP handles error messages and diagnostics, and IGMP manages multicast group membership). This makes TCP the protocol most closely tied to IP in the familiar TCP/IP naming.

IP handles addressing and routing but doesn’t guarantee delivery or order. TCP sits on top of IP to provide reliable, connection-oriented transport with sequencing, error checking, and flow control. Because they work together to enable dependable end-to-end communication, the combination is ubiquitously written as TCP/IP. The other protocols—UDP, ICMP, and IGMP—are part of the IP suite but serve different roles (UDP is another transport option without reliability guarantees, ICMP handles error messages and diagnostics, and IGMP manages multicast group membership). This makes TCP the protocol most closely tied to IP in the familiar TCP/IP naming.