CCNA R&S Exam Prep Question of the Week


What information does a router running a link state protocol use to build and maintain its topological database? Choose two.

A. LSAs from other routers
B. SAP messages sent by other routers
C. hello packets
D. TTL packets from designated routers
E. Beacons received on point-to-point links
F. Routing tables received from other link state routers

The correct answer is A and C.

First OSPF uses link state advertisements (LSA) to pass routing information from router to router that contribute to the link state database. Once the LSAs are received and acknowledged, the hello packets are used as a keep alive so the router knows to hold on to the information received from the other router.

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CCNAX v2.0 – CCNA Routing and Switching Boot Camp
ICND1 v2.0 – Interconnecting Cisco Networking Devices, Part 1
ICND2 v2.0 – Interconnecting Cisco Networking Devices, Part 2

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