EIGRP and OSPF authentication

If you’re wondering if you should use this I think you should. Having any traffic unauthenticated is just stupid and you’re asking for issues on your network with someone coming in and sniffing your traffic and discovering that you have hello messages with no or plain text authentication set. One shouldn’t have to explain the benefits; however, do understand that EIGRP has the advantage of using multiple keys in a ring that have expirations which helps rotate keys to prevent someone from getting a key that has been in use for years. OSPF does not have such a feature in IOS.