Secure database ports

All network security starts with strict and proper firewall rules on interfaces that are exposed to the internet, allowing only the absolute minimum traffic in or out of the internal network. Firewall security is especially important when running your infrastructure in a public cloud. Wherever you host your clusters, DataStax strongly recommends using a firewall on all nodes in your cluster.

Begin with a restrictive configuration that blocks all traffic except SSH. Then, open up the following ports in compliance with your security requirements to allow communication between the nodes. If these ports are not opened, the node acts as a standalone database server rather than joining the cluster when you start Hyper-Converged Database (HCD) on a node.

If the cluster uses SSL only, close any non-SSL ports that have dedicated SSL ports. To ensure communication is not disabled to any non-SSL clients, DataStax recommends testing the configuration in a staging environment before enabling the firewall in production environments.