Book excerpt: With this concise, problem-solving guide, networking professionals will learn how to identify network security threat implement uniform security throughout their networks, secure remote dial-in access with CiscoSecure ACS and Cisco IOS AAA features, protect Internet access on their perimeter routers with the CiscoSecure IOS firewall software, and implement secure VPNs using IPSec and Cisco Encryption Technology. Step-by-step instructions and immediate solutions will help administrators implement and update security defenses. Every configuration in this book has been completely tested and perfected with actual Cisco routers.