1. A method for evaluating an access from a first network node to a second network node, the method comprises: receiving information representative of the first network node and of the second network node; wherein the second network node is accessible to the first network node and wherein an access of the first network node to the second network node is associated with a violation of a first policy access rule or associated with a second policy access rule; generating security metrics associated with an access from the first network node to the second network node in response to: attack characteristics of a first group of start network nodes that can attack the first network node and attack characteristics of a second group of target network nodes that can be attacked from the second network node; and wherein the method comprises evaluating a relative imposed risk associated with a predecessor network node in response to a maximal relative imposed risk associated with each of multiple successor network nodes; wherein the predecessor network node and the multiple successor network nodes are coupled to the first and second network nodes.