Home > Storage > ObjectScale and ECS > Product Documentation > ECS PCI DSS Compliance > Requirement 1: Install and maintain a firewall configuration to protect cardholder data
A firewall is critical to the protection of an enterprise data center as it is responsible for limiting external traffic from accessing the internal network. In the network hierarchy, an ECS cluster must be located securely behind a firewall. All the nodes within an ECS cluster shall only have external network access through a firewall, ensuring all traffic interacting with ECS is filtered and approved through a firewall. The configuration of this requirement is outside the scope of the ECS cluster.