OSPF Type4 Message / LSU Packet (Link State Update)

Similar to LSR, LSU (Link State Update) is the response/reply to LSR. Each Link State Update packet carries a collection of link state advertisements one hop further from its origin.   Consider the simple below topology with two Routers: LSU’s are generated in response to the LSR’s. It is obvious from the below detail, spend some time with it to understand it fully:   Related