VersionOpcodeChecksum
Flags
Sequence
Acknowledgement
Virtual Router IDAustonomous System (AS)

Believe me or not, aside from passing an exam there is another important reason why you should know what is inside the EIGRP packet header. Any hypothesis?

The Job Interview

You thought you know everything when you got the Cisco professional level certification but what happens when the interviewer asked you about what is inside the EIGRP packet header? You memorized all the configurations commands. You know what is BGP route reflector. You know how to do unequal load balancing in EIGRP. You even know how to configure fabric path, ASA firewalls, and do site-to-site VPN. You know everything you did in your laboratory but you forgot what is inside the EIGRP packet header.
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