About the Author John Chirillo, CISSP, ISSAP, ASE, CCDA, CCNA, CCNP, SCSECA, is a Senior Internetworking Engineer at ValCom and the author of several computer security books. John has also achieved certifications in numerous programming languages and is responsible for dozens of published security exploits and alerts throughout numerous listings. He has actively participated in core security developments of various UNIX flavors under the GNU. John can be reached at tiger@tigertools.net.About the Co-Author Edgar Danielyan, CISSP, ISSAP, ISSMP, CISA, MBCS, SCSA, SCNA, is Information Systems Audit Manager with Deloitte & Touche in the city of London. Before joining Deloitte, he had been an… independent security consultant since 1999. He is also the author of Solaris 8 Security (New Riders, 2001) and technical editor of a number of books on Solaris, security, UNIX, and internetworking. His personal web site can be found at www.danielyan.com.About the Technical Editor Tom Brays, SCSA, SCNA, SCSECA, MCP, is a network administrator for a large telecommunications firm and the technical editor and contributing author of several computer books. He can be reached at tombrays@techie.comAbout LearnKey LearnKey provides self-paced learning content and multimedia delivery solutions to enhahce personal skills and business productivity. LearnKey claims the largest library of rich streaming-media training content that engages learners in dynamic media-rch instruction complete with video clips, audio, full motion graphics, and animated illustrations. LearnKey can be found on the Web at www.LearnKey.com.