Practical Network Scanning

DMZ to Internal Access Policy 

Internal systems hold valuable data and are not exposed directly to the internet, but a DMZ plays a proxy role in between. Just imagine that a DMZ server is compromised and the internal LAN is wide open. In this situation, attackers could find a way into your network.

Let's take a look at the example for setting up a web server in DMZ.

You must set a baseline for what you want to protect and consider scalability, availability, and agility. You have the freedom to choose the number of firewalls for setting up a DMZ, but two firewalls would be a good start. With two firewalls, you can put front-line servers behind a perimeter firewall (DMZ) and internal resources under a different firewall.

You can also have multiple ...