Microsoft® Lync Server 2010 Unleashed

Back-to-Back Firewalls

The ideal approach to any perimeter network or DMZ is to utilize two different security devices where one provides a layer of defense from the Internet to the perimeter network and the second provides another layer of defense by filtering traffic between the perimeter network and internal network. The Lync Server Edge Servers are situated between the two firewalls in the perimeter network. This approach is illustrated in Figure 27.4.

Figure 27.4 Back-to-Back Firewalls

Tip

This configuration is generally considered the most secure because even if an attack compromises the external firewall, the internal firewall still isolates ...