Encapsulating OSPF Messages

Open Shortest Path First (OSPF) runs over the Internet Protocol’s network layer. So, Open Shortest Path First (OSPF) encapsulated only by IP and local data-link headers. Encapsulating OSPF messages transmitting over an Ethernet link contain the following information:

OSPF Header

  • Data Link Frame Header– This header contains the destination multicast MAC addresses.
  • IP Packet Header–This header contain the IPv4 protocol field 89 indicates an OSPF packet. It also identifies one of two OSPF multicast addresses, 224.0.0.5 or 224.0.0.6.
  • OSPF Packet Header–This header shows the OSPF packet type and also show the router ID and the area ID.
  • OSPF Packet Type Specific Data– This header contains the OSPF packet type information