With Neutron FWaaS now installed, we can use this service through the Neutron API and command line. This allows us to create perimeter firewall policies between our routed Neutron networks.

With a Neutron firewall in place on the L3 router, any traffic traversing that router will be inspected there before it is allowed to continue. This allows us to have a firewall between layers of an application. For example, you may have a standard multi-tiered web application where a web server communicates with a database server. With Neutron firewalls in place, we can allow only database traffic to traverse between the database and the web server. Policies at the router level can be seen as traditional edge perimeter firewall policies, whereas security groups can be seen as similar to host-based security. Policy driven security also fits well with traditional network security teams moving to an OpenStack environment and allows standards to be controlled at the network level, rather...