CCENT Cisco Certified Entry Networking Technician Study Guide: (ICND1 Exam 640-822), 2nd Edition

Introduction to Security

You see this a lot—typically, in medium to large enterprise networks, the various strategies for security are based on some recipe of internal and perimeter routers plus firewall devices. Internal routers provide additional security to the network by screening traffic to various parts of the protected corporate network, and they do this using access lists.

Access lists are beyond the scope of this book, but they're covered in CCNA: Cisco Certified Network Associate Study Guide, Seventh Edition (Sybex, 2011).

Figure 9.1 shows where each of these types of devices is found.

FIGURE 9.1 A typical secured network

To protect ...