There are provided a computer-implemented connectivity manager and a method of managing connectivity between resources in a computer network using the connectivity manager. The method comprises: generating a connectivity specification of a given application, said specification comprising one or more connections generated in accordance with received by the connectivity manager user's definition of network resources and connections therebetween required to the given application, each connection characterized by one or more source resources, one or more destination resources and services therebetween; recognizing, by the connectivity manager, all access-control devices among the plurality of access-control devices, which are involved in controlling all connections comprised in said connectivity specification; identifying, by the connectivity manager, in each of the recognized access-control devices, access-control rules engaged in control of connections comprised in said connectivity specification; and mapping, by the connectivity manager, said connections comprised in said connectivity specification to the identified engaged access-control rules.