Which of the following best describes the type of packets used by OSPF routers to exchange updates on a point-to-point link?
IP packets sent to an IP multicast address.
TCP packets sent to an IP multicast address.
IP packets sent to an IP unicast address.
UDP packets sent to an IP multicast address.
Comprehensive and Detailed Explanation From Exact Extract:
FromNokia 7750 SR OS OSPF Guide — OSPF Packet Transmission Section:
“OSPF uses protocol 89 over IP and transmits updates to multicast address 224.0.0.5 (AllSPFRouters) on point-to-point and broadcast links.”
No TCP or UDP used.
Pure IP protocol with protocol number 89.
Multicast address 224.0.0.5 is used for neighbor discovery and update transmission.
Thus, correct answer isA.
