I will add my two cents as well. When I have a new consultant shadowing me and he asks what he should learn I always list Wireshark as one of the first things to learn. There is no aspect of networking that does not benefit from knowing how to read the packets. It is helpful in diagnostics, forensics, planning, learning, and so much more. It is a very good foundation for almost all other certs. Everything in a network travels on the cables and if you can understand it, you will be among the top. Of course, none of them ever seem to understand this so I guess I have a job security for a little more time.
MCITP:EA | MCTS(x5) | MCSA+ | MCSE+ | Security + | CCNA | WCSP |
DSCE | PCT |CIW Security Analyst | CSSA