Routing with OSPF – Part 3 (OSPF Packet Types) ⋆ IpCisco

OSPF use OSPF Packet sto communicate and establish OSPF Operation. There are different Packet types in OSPF and in this article, we will focus on these OSPF Packet Types. We will explaint each Packet and see the duty of this packet.

In almost, every technical job interview, OSPF Packet Types are asked.So, it is also important for your interviews.

There are 5 types of OSPF Packets. These OSPF Packets are :

• Hello
• Database Description (DBD)
• Link State Request (LSR)
• Link State Update (LSU)
• Link State Acknowledgement (LSAck)

These OSPF Packet Types are mentined in the “Packet Type” area.

In OSPF Header, the following packet types are mentioned with the above numbers in the message type field.

OSPF Header

OSPF (Open Shortest Path First) Header

Now, let’s check these OSPF Packet Types more detaily. Here, we will show OSPF Packets to you with various Packet captures.

OSPF Hello Packet

OSPF Hello Packet is used between directly connected neighbours for Neighbour Establishment.

You can check the below OSPF Hello Packet capture to see a real life example of this Packet.

OSPF (Open Shortest Path First) Hello Packet

OSPF Database Description (DBD) Packet

OSPF Database Description (DBD) Packet is a set of LSAs belonging to the topology and their Router ID. Here, when a newer LSA is seen then, it is requested with an LSR(Link State Request).

You can check the below OSPF DD Packet capture to see a real life example of Database Description Packet.