What information can be used by a router running a link-state protocol to build and maintain its
topological database? (Choose two.)
A.
hello packets
B.
SAP messages sent by other routers
C.
LSAs from other routers
D.
beacons received on point-to-point links
E.
routing tables received from other link-state routers
F.
TTL packets from designated routers
The link-state advertisement (LSA) is a basic communication means of the OSPF routing protoco
In the Open Shortest Path First (OSPF) communications protocol – which enables network routers to share information with each other, a HELLO packet is a special packet (message) that is sent out periodically from a router to establish and confirm network adjacency relationships.
Link-state advertisements are crucial to OSPF and building the topology. It is how routers know about each other’s links and who connects to who across an area. OSPF uses area’s to define sets of routers. They can be as small or as large as you want within reason. All areas MUST connect back to Area 0 – virtual links are an exception – so it is paramount that Area 0 is stable.