If there is no perimeter network, a last-resort option is to leave both Edge Server adapters as part of the internal network. In this configuration, both Edge Server interfaces are part of the internal network, and NAT can be used to expose the required Edge services.
This approach is not recommended at all and should be avoided if possible. Instead, take the time to plan for a perimeter network if one does not exist prior to the Lync Server deployment. This topology is included here only as an example of how not to deploy Lync Edge Servers.
Although this approach can work, from a technical perspective it is not ideal for the following reasons, as shown in Figure 27.6:
• The only firewall exception for the Edge ...