Protecting the perimeter

Perimeter firewalls (or clusters) are used to create the following enforcement points:

• Between internal clients (or hosts) and the core (Figure 2.8)
• Between external clients and publicly accessible resources in data centers (as shown in Figure 2.10):

Figure 2.10 – Perimeter networks segmentation

• Between internal clients (or hosts) and resources on the internet and extranets (as shown in Figure 2.11):

Figure 2.11 – Perimeter networks segmentation

• Between specific segments of data centers and resources on the internet and extranets (as shown in Figure 2.12):

Figure 2.12 – Perimeter networks segmentation

• Between groups of internal clients (or hosts) (as shown in Figure 2.13):

Figure 2.13 – Perimeter networks segmentation

A perimeter is comprised of segments behind firewalls (or clusters...