Which PDU type is sent by an IS-IS router when it detects that its link-state database is out of date?
Click on the arrows to vote for the correct answer
A. B. C. D.D
The Intermediate System to Intermediate System (IS-IS) is a link-state routing protocol used to exchange routing information between routers in a network. When an IS-IS router detects that its link-state database is out of date, it sends a specific Protocol Data Unit (PDU) to request updated information from other routers in the network.
The correct answer to this question is B. link state PDU. A link-state PDU is sent by an IS-IS router when it detects that its link-state database is out of date. This PDU contains information about the router's neighbors and the state of their links. By exchanging this information with other routers in the network, the router can update its link-state database and ensure that it has the most up-to-date information about the network topology.
Option A, hello PDU, is used by IS-IS routers to discover and establish adjacencies with their neighbors. Option C, complete sequence number PDU, and option D, partial sequence number PDU, are used by IS-IS routers to maintain synchronization and ensure consistency between their link-state databases and those of their neighbors. However, they are not specifically used to request updated information when a router's link-state database is out of date.
In summary, the correct answer to this question is B. When an IS-IS router detects that its link-state database is out of date, it sends a link state PDU to request updated information from other routers in the network.