Skip to content
GATETECH
Official PYQ · 2025Set 2 · Q8Fragmentation and IP Addressing, IPv4, CIDRMCQ1 mark

GATE CS 2025 Set 2 Q8 — Fragmentation and IP Addressing, IPv4, CIDR

Explain with AI

​​​A machine receives an IPv4IPv4 datagram. The protocol field of the IPv4IPv4 header has the protocol number of a protocol XX.

Which ONE of the following is NOT a possible candidate for XX?
Choose one option
View worked solution

Answer: D

The Protocol field in the IPv4 header identifies the next level protocol to which the IP payload should be passed. It indicates the protocol encapsulated directly inside the IP datagram.

  • ICMP (Internet Control Message Protocol): Encapsulated directly inside the IP datagram. Its IP protocol number is 1.
  • IGMP (Internet Group Management Protocol): Encapsulated directly inside the IP datagram. Its IP protocol number is 2.
  • OSPF (Open Shortest Path First): Encapsulated directly inside the IP datagram. Its IP protocol number is 89.
  • RIP (Routing Information Protocol): RIP is an application-layer routing protocol that is encapsulated inside UDP segments (using UDP port 520). Therefore, the Protocol field in the IPv4 header of a packet carrying a RIP message contains the protocol number for UDP (which is 17), not RIP itself.

Thus, RIP is NOT a possible candidate for the protocol field XX in the IPv4 header.

Free practice · Your answers on this page are not saved.

Published
Report a correction
Keep exploringMore Fragmentation and IP Addressing, IPv4, CIDR questions