Which of the following assertions is FALSE about the Internet Protocol (IP)? A. It is possible for a computer to have multiple IP addresses B. IP packets from the same source to the same destination can take different routes in the network C. IP ensures that a packet is discarded if it is unable to reach its destination within a specified number of hops D. The packet source cannot set the route of an outgoing packet; the route is determined only by the routing tables in the routers

GATE 2003 · Computer Networks · IP Addressing · medium

Answer: Option D is FALSE. The correct answer is D.

1. Verify options A, B, C as TRUE: A: A computer can have multiple network interfaces each with a different IP address (multihoming) — TRUE. B: IP is connectionless; each packet is routed independently, so packets between the same src and dst can take different paths depending on router table states — TRUE. C: The TTL field in every IPv4 header is decremented by 1 at each router. When TTL = 0, the router discards the packet and typically sends an ICMP Time Exceeded message back to the source — TRUE.
2. Evaluate option D: D claims: 'The packet source cannot set the route of an outgoing packet; the route is determined only by the routing tables in the routers.' This is FALSE. IPv4 defines an Options field in the IP header. Two source routing options exist: 1. Loose Source Routing (LSR): source specifies a list of intermediate routers the packet MUST pass through (other hops can be added by routers). 2. Strict Source Routing (SSR): source specifies the exact complete route. Thus the source CAN influence or completely specify the route using these IP options, making option D false.