Method of unblocking external computer systems in a computer network infrastructure, distributed computer network having such a computer network infrastructure as well as computer program product

Abstract

A method of unblocking external computer systems includes transmitting an authentication packet from an external computer system, configured outside the computer network infrastructure, to a broker computer system within the computer network infrastructure, wherein the authentication packet contains signed information for authentication of the external computer system, automatically transmitting the authentication packet from the broker computer system to at least one processing computer system within the computer network infrastructure, wherein the processing computer system keeps predetermined network ports at least temporarily closed wherein, however, the processing computer system is capable of accessing the broker computer system to fetch the authentication packet from the broker computer system, unblocking at least one selective network port by the processing computer system for communication with the external computer system, and establishing a connection to the selectively unblocked network port of the processing computer system by the external computer system.