1. A method to be executed by a computer device for detecting interactions on a forwarding element in a network (N), wherein the forwarding element (FE) forwards data according to rules, installable on the forwarding element (FE), and wherein a rule set (RS) is installed on the forwarding element (FE), and wherein the rule set (RS) comprises rules (R), and wherein a rule comprises a match set (M) and at least a corresponding action set (A), wherein the match set (M) comprises at least one match field (f) and wherein the action set (A) comprises one or more actions (a) wherein action set (A) to be performed when matching the match set (M) and a priority (P) assigned to each rule (R), comprising the steps of: a) computing (S 1 ) one or more relations between the match sets (M) based on match field relations (f), b) computing (S 2 ) one or more relations between the action sets (A), c) computing (S 3 ) one or more interactions between the rules (R) based on the computed relations between the match sets (M) and the action sets (A), wherein each rule (Rx) is tested against another rule (Ry) for determining the interaction, wherein all of duplication, redundancy, generalization, shadowing, correlation, inclusion, and extension as rule interactions are determined, and d) reducing (S 4 ) the rule set (RS) to an actual rule set (ARS) according to the computed interactions so that the actual rule set (ARS) comprises only rules (R) with no interactions among the rules, wherein: a2) the steps a), b), c) and d) are performed (V 1 ) for each forwarding element (FE) in the network (N), b2) one of the forwarding elements (FE) is selected (V 2 ), c2) a neighbor list of next neighbors (NNFE) with regard to the selected forwarding element (SFE) is determined (V 3 ), d2) steps c1) to e1) are performed (V 4 ), as follows: c1) performing (T 3 ) the steps a), b), c) and d) for each of the forwarding elements (NNFE) in the neighbor list for obtaining an actual rule set (ARS) for each of the forwarding elements (NNFE), d1) determining (T 4 ) one or more interactions between the actual rule sets (ARS) of two neighbor forwarding elements (FE, NNFE), e1) reducing (T 5 ) the actual rules sets (ARS) according to the computed interactions so that the actual rules sets (ARS) comprise only rules with no interactions to the rule (R) of the respective other actual rule set (ARS), e2) the disjoint actual rule sets are merged (V 5 ) into one new actual rule set (ARS) representing both the neighbor forwarding element (NNFE) and the selected forwarding element (SFE), f2) a merged forwarding element (MFE) is defined (V 6 ) with the new actual rule set (ARS) as new selected forwarding element (SFE), and g2) performing (V 7 ) the steps c2) to f2) iteratively until a predetermined number have been merged to two forwarding elements (FE).