Alibaba Cloud's Cloud Firewall is the industry's first firewall as a service (FWaaS) solution targeted for public clouds. It allows you to centrally manage the control policies for the access traffic from the Internet to your ECS instances (internet traffic), and provides micro-isolation policies for the access traffic between ECS instances (intranet traffic). With the built-in Intrusion Prevention Service (IPS), Cloud Firewall gives you full visibility of network-wide traffic and access relationships between ECS. Cloud Firewall is the primary infrastructure that you need to deploy to ensure network security of the businesses that you have migrated onto Alibaba Cloud.