Table 8-2 OSPF Packet Types

Question 1

Hello

Answer 1

These packets are for discovering and maintaining
neighbors. Packets are sent out periodically on all OSPF
interfaces to discover new neighbors while ensuring that
other adjacent neighbors are still online.

Question 2

Database
description
(DBD) or (DDP)

Answer 2

These packets are for summarizing database contents.
Packets are exchanged when an OSPF adjacency is first
being formed. These packets are used to describe the
contents of the LSDB

Question 3

Link-state
request (LSR)

Answer 3

These packets are for database downloads. When a router
thinks that part of its LSDB is stale, it may request a
portion of a neighbor’s database by using this packet type.

Question 4

Link-state
update (LSU)

Answer 4

These packets are for database updates. This is an explicit
LSA for a specific network link and normally is sent in
direct response to an LSR.

Question 5

Link-state ack

Answer 5

These packets are for flooding acknowledgments. These
packets are sent in response to the flooding of LSAs, thus
making flooding a reliable transport feature.