OSPF Packet Types

Open Shortest Path First use OSPF Packets to communicate and establish OSPF Operation. There are different OSPF Packet Types and in this lesson, we will focus on these OSPF Packet Types. We will explain 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 Packet Types 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 of OSPF Header.

 

 

In OSPF Header, the following packet types are mentioned with the above numbers in the message type field. Now, let’s learn each of these packets with the screenshots of Wireshark Packet Analyzer.

 

OSPF Header 

OSPF (Open Shortest Path First) HeaderNow, let’s check these OSPF Packet Types more detaily. Here, we will show OSPF Packets to you with various Packet captures.

 

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

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You can also learn Cisco OSPF Configuration

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What is 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.

 

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You can also check other CCNP lessons

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OSPF (Open Shortest Path First) DD(Database-Description) Packet

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What is OSPF Link State Request (LSR) Packet?

OSPF Link State Request (LSR) Packet is used to request new LSA (Link State Advertisements).

 

You can check the below OSPF Link State Request Packet capture to see a real life example of a Link State Request Packet.

 

OSPF (Open Shortest Path First) LSR (Link State Request)

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What is OSPF Link State Update (LSU) Packet?

OSPF Link State Update (LSU) Packet is used to reply to the requestes. Basically it is a LSR reply with LSAs.

 

You can check the below OSPF Link State Update Packet capture to see a real life example of a Link State Update Packet.

 

OSPF (Open Shortest Path First) LSU (Link State Update)

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What is OSPF Link State Acknowledgement (LSAck)?

OSPF Link State Acknowledgement (LSAck) Packet is the confirmation of the receipt information. It is an Acknowledgement mechanism.

 

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

 

 

OSPF (Open Shortest Path First) LSAck (Link State Acknowledgment)In this article, we tried to explain OSPF Packet Types with real life packet captures.To see this Packet types with captures is better to realize what is these packet in real. Because, generally, in the diagrams, we see these packet tyes only with in a box ;)

 

OSPF article series is continues. To learn more, keep on…

 

OSPF (Open Shortest Path First) Packet Types