A system administrator and network engineer since 1987, he speaks at conferences around the world on topics ranging from firewall security to time management. He is the author of Time Management for System Administrators from O'Reilly; along with Christine Hogan, co-author of the book The Practice of System and Network Administration from Addison-Wesley and most recently with Peter H. Salus he has published a compilation of the best April Fools jokes created by the IETF entitled The Complete April Fools' Day RFCs.