Hi again OSPF uses message types. So, there are five message types in OSPF. The first message type is the hello and hello is basically used to discover adjacencies. So a router will send a Hello packet and and that's how it discovers the adjacency and neighboring devices using Hello packet it's it maintains and builds the neighboring neighbors ships and it creates OSPF peers at both ends of the link and and the router that adjacent to it has to agree to those same parameters. So hello is the is the mechanism that OSPF uses The second message type is dp D. dp D is basically once the adjacency have been formed membership relationship is formed. dp D is important to maintain the synchronization of the database.

And it It usually compares and syncs the database between the routers. The third message packet or message type is LSR. LSR is basically a packet that's sent whenever the router thinks that there are some missing links and it needs an information so, an LSR is sent in the form of a request. It receives the response back for the LSR that is sent in a form of LSU And that's how it's and it's basically received to, to the neighbors that are directly connected. So LSU packet, that's the function of the LSU packet. And now each link state advertisement that is received is acknowledged by another packet which is known as LSA acknowledgement packet.

So, so that's all about the message types that OSPF uses. Let's move on to the next topic.