Todd Lammle is the authority on CompTIA and Cisco certifications and is certified in most CompTIA and Cisco certification categories.

He is a world-renowned author, speaker, trainer, and consultant. Todd has three decades of experience working with LANs, WANs, and large enterprise licensed and unlicensed wireless networks, and lately he's been concentrating on implementing large Cisco Security networks using Snort, Firepower/FTD, ISE, and Stealthwatch.

His years of real-world experience are evident in his writing; he is not just an author but an experienced networking engineer with very practical experience from working on the largest networks in the world, at such companies as Xerox, Hughes Aircraft, Texaco, AAA, Cisco, and Toshiba, among many others.

Todd has published over 100 books, including the very popular CCNA: Cisco Certified Network Associate Study Guide, CompTIA Network+ Study Guide, CCNA Wireless Study Guide, CCNA Data Center Study Guide, SSFIPS (Firepower), and CCNP Security, all from Sybex.

He runs an international consulting and training company based in Colorado, where he spends his free time in the mountains playing with his golden retrievers.

You can reach Todd through his website at www.lammle.com.

About the Technical Editor

Chris Crayton is a technical consultant, trainer, author, and industry-leading technical editor. He has worked as a computer technology and networking instructor, information security director, network administrator, network engineer, and PC specialist. Chris has authored several print and online books on PC repair, CompTIA A+ exam, CompTIA Security+ exam, and Microsoft Windows. He has also served as technical editor and content contributor on numerous technical titles for several of the leading publishing companies. He holds numerous industry certifications, has been recognized with many professional and teaching awards, and has served as a state-level SkillsUSA final competition judge.