By default, cluster nodes monitor each other's status using the UDP protocol. Some networks only allow TCP to be used. In this situation, you can add the
TCPPING protocol stack to your configuration and use it as the default mechanism. These configuration options are available in the command-line based Management CLI.
mod_cluster subsystem also uses UDP communication by default, and you can choose to use TCP here as well.
Refer to the following two procedures to configure JGroups and mod_cluster subsystems to use TCP for network communication: