Who controls the routing protocol that glues the network together controls the network. Defend the protocol well, and you would never be wrong in applying the strictest countermeasures possible. Lose it, and the control of a whole network could be lost. RIP security vulnerabilities are an old issue; however, the example with possible RIPv2 replay attacks demonstrates that looking deeper into this issue is not time wasted .
IGRP is slowly dying, but a chance to encounter an IGRP network is always an option somewhere. After all, if it works and I am familiar with it, why change anything? No one has really looked into attacking EIGRP, spare for the basic support of this protocol in Cain and the enumeration capabilities of ass . We hope that you have enjoyed our brief journey into the virgin EIGRP security world and have learned something about approaching a proprietary protocol from a hacker's perspective.
OSPF is all around and will stay with us for a very long time, so understanding how its hierarchical structure affects its security and what the attackers can do to abuse this protocol is instrumental.
Finally, it is symbolic that the book ends at looking into BGPv4 exploitation. BGPv4 holds the modern Internet together. The consequences of its successful exploitation can be truly disastrous. Fortunately for us (and the Internet), BGPv4 is not as vulnerable as it is claimed to be by many. Nevertheless, a skilled rat may slip into a few holes, and we must stay vigilant so that the worst nightmares of the networking community will never come to life.