The present disclosure provides an approach for generating one or more firewall rules to regulate communication between containerized services running within containers. The approach includes determining which services communicate with each other, independently of in which containers the services execute. The determining occurs over a period of time. If two services communicated with each other during the period of time, then the firewall allows the services to continue communicating, but only over the same ports as used during the period of time. If two services did not communicate during the period of time, then the firewall does not allow the services to communicate after the expiration of the period of time. In some embodiments, redetermining the communication flow over a new period of time may occur after the initial period of time so as to refresh the firewall rules.