Cisco author, speaker, and trainer Todd Lammle is considered the authority on all things networking, and his books have sold almost a million copies worldwide. This all-purpose CCNA study guide methodically covers all the objectives of the ICND1 (100-101) and ICND2 (200-101) exams as well as providing additional insight for those taking CCNA Composite (200-120) exam. It thoroughly examines operation of IP data networks, LAN switching technologies, IP addressing (IPv4/IPv6), IP routing technologies, IP services, network device security, troubleshooting, and WAN technologies.