OSPF Packets

Question 1

LSA - Link state Advertisement

Answer 1

routers use LSA to advertise the routing topology to all other local routers in the same OSPFv2 area. Sent in Multicast

Question 2

LSDB - Link State Database

Answer 2

Stores recieved LSA packets after the routers enable OSPFv2 to use SPF algorithm to calculate the routes

Question 3

DBD - Database Description

Answer 3

When an adjacency is initialized, OSPFv2 exchanges DBD packets to describe the content of the toplogical database

Question 4

LSR - Link State Request

Answer 4

if a router notices that parts of its topological database are outdated, it will send a Link State Request for more updated versions of those components. LSRs are multicast

Question 5

LSU - Link Stat Update

Answer 5

messages are responses to LSR messages

LSU are sent in unicast

Question 6

Dijkstra Algorithm

Answer 6

By calculating all routes to each network in the topology using Djikstra Algorithm, OSPFv2 creates a map of the network called an SPF tree. The SPF tree is stored in a database on the router called Link State Database