Question

An OSPF router receives an LSA. The router checks its sequence number and finds that this number is lower than the sequence number it already has. What does the router do with the LSA?

(a) ignores the LSA

(b) adds it to the database

(c) sends newer LSU update to source router

(d) floods the LSA to the other routers

I got this question in unit test.

This key question is from OSPF Configuration topic in portion Network Layer of Computer Network

Answer 1

Right choice is (c) sends newer LSU update to source router

Easiest explanation: An OSPF router receives an LSA. If the router checks its sequence number and finds that this number is lower than the sequence number that it already has, the router sends newer LSU update to source router. The router then adds it to the database and floods it to the other routers.