What type of packets do link-state protocols use to share routing information among neighbors?

Link-state protocols utilize Link-State Advertisements (LSAs) to share routing information among neighboring routers. LSAs are specific types of packets that contain information about the state of a router's links, including the cost of reaching those links and the status of the links to other routers in the network. By exchanging LSAs, routers build a complete and accurate map of the network topology, which allows them to calculate the shortest path to each destination using algorithms like Dijkstra’s.

The other choices do not accurately represent the method link-state protocols use. Data Link Layer packets are related to how data is framed and sent over a physical medium, but do not encompass the routing information involved in LSAs. UDP and TCP packets, being transport layer protocols, focus on delivering messages between applications over IP networks rather than on routing information among routers.