1. OSPF is a "routing" protocol. It is used by routers (inside an ISP or corporation) to figure out which paths packets should take when forwarded through the network. Key point: OSPF can easily be subverted by "local" hackers. This means that hacker generally has to be within network area he/she wishes to subvert. The hacker will either pretend to be a router, or spoof packets from nearby routers. The most common technique is to "advertise" false information (spoof Link State Advertisements (LSA)). From Hacking-Lexicon