The Open Shortest Path First (OSPF) protocol is an IGP that routes packets within a single AS. OSPF uses link-state information to make routing decisions, making route calculations using the shortest-path-first (SPF) algorithm (also referred to as the Dijkstra algorithm). Each router running OSPF floods link-state advertisements (LSAs) throughout the AS that contain information about that router's attached interfaces and routing metrics. Each router takes the information in these link-state advertisements and creates a complete routing table for the network.
The JUNOS software supports OSPF Version 2, including virtual links, stub areas, and authentication. It does not support type-of-service (ToS) routing.
In OSPF, a single AS can be ...