IP Protocol Key Traits Explained | Generated by AI
Question: Which of the following best describes the characteristics of the IP protocol?
A. Connection-oriented, reliable packet delivery protocol
B. Connection-oriented, unreliable packet delivery protocol
C. Connectionless, reliable packet delivery protocol
D. Connectionless, unreliable packet delivery protocol
Answer:
The correct answer is D. Connectionless, unreliable packet delivery protocol
Detailed Explanation:
The IP protocol (Internet Protocol) has the following fundamental characteristics:
-
Connectionless (面向无连接 / 无连接)
IP does not establish a connection before sending data.
Each IP datagram (packet) is sent independently and carries its own full destination address.
There is no handshake, no setup phase, and no teardown phase — unlike TCP. -
Unreliable (不可靠)
IP makes a best-effort delivery attempt but provides no guarantees that:- the packet will arrive at all
- packets will arrive in the correct order
- packets will arrive without duplication
- packets will not be corrupted
- packets will not be lost
IP itself does not perform:
- retransmission of lost packets
- reordering of out-of-order packets
- duplicate detection
- flow control
- congestion control
All of these reliability features (if needed) are provided by higher-layer protocols — most commonly TCP.
Quick comparison of common protocols:
| Protocol | Connection-oriented? | Reliable? | Main responsibility | Layer |
|---|---|---|---|---|
| IP | No | No | Addressing & best-effort routing | Network (Layer 3) |
| TCP | Yes | Yes | Reliable, ordered, error-checked delivery | Transport (Layer 4) |
| UDP | No | No | Simple, fast, connectionless datagram | Transport (Layer 4) |
Why the other options are wrong:
- A. Connection-oriented, reliable → This describes TCP, not IP.
- B. Connection-oriented, unreliable → No major protocol works this way (connection setup without reliability makes little sense).
- C. Connectionless, reliable → Does not exist in the standard TCP/IP stack (reliability almost always requires connection state to track sequence numbers, acknowledgments, retransmissions, etc.).
Key exam takeaway (very frequently tested):
IP = connectionless + unreliable (best-effort)
TCP = connection-oriented + reliable
UDP = connectionless + unreliable
Correct answer: D
References:
- None (standard definition from RFC 791 – Internet Protocol and common networking textbooks)