What information does a router running a link-state protocol use 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
Explanation:
http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094e9e.shtml