Cisco Systems, Inc., is the largest manufacturer of networking systems in the world. It dominates the router and switch market to the extent that Cisco routers and switches are considered by many networking professionals to have set the standard for all other companies. Cisco routers, switches, and other equipment keep running without problems, are readily upgraded, are easily adapted to new network configurations, and are compatible with virtually every transport or access method. "Cisco Networking For Dummies, 2nd Edition" presents the facts, concepts, processes, and applications that Cisco network administrators need to know in step-by-step lists, tables, figures, and text - without long explanations. This easy-to-understand guide covers : layering a Cisco network; transporting data over the Internetwork; routing and switching: inside and out; working with WAN technologies; designing your own network; working with firewalls, proxies, and other safety measures; and implementing VPNs. Certification candidates may find "Cisco Networking For Dummies, 2nd Edition" to be an excellent study aid for preparing for the CCNA (Cisco Certified Networking Associate) or the CCDA (Cisco Certified Design Associate) exams. This thoroughly updated reference gets down to the serious business of: transporting on Layer 4 interface; wiring up a personal area network; flying fast with UDP; converting hexadecimal numbers; subnetting a Class A network; virtually segmenting the LAN; mapping IPs to DLC working with IPX access lists; and tunneling across the Internet. Expert author (and natural comic) Ron Gilster (CCNA, A+, Network+, i-Net+, MBA, and AAGG) boasts decades of computing experience. He is the bestselling author of a number of career certification books, including "A+ Certification For Dummies", "Network+ Certification For Dummies", "i-Net+ Certification For Dummies", "Server+ Certification For Dummies", and "CCNA For Dummies", plus several books on networking, the Internet, computer and information literacy, and programming.