High Availability Cluster components and their relationship with the network

The High Availability Cluster (HAC) components require network connectivity to work properly if they have been distributed across multiple machines, and even in cases where the components are on one machine.

The HAC components communicate with each other using TCP network protocols. A firewall that has not been configured to allow these ports open can block communication between the cluster members.

The HAC components uses the following network ports to communicate between its components by default or by convention. You can perform a network port scan on a host to determine if it is listening on a port.

Network diagram