The invention relates to an intermediate network (1) in a ring topology for setting up a connection between two network domains (2a, 2b), having a first marginal node (6a) and a second marginal node (7a), which are marginal nodes in a first network domain (2a) and which are connected to one another by means of a first network connection (9a) within the first network domain (2a), a third marginal node (6b) and a fourth marginal node (7b), which are marginal nodes in a second network domain (2b) and which are connected to one another by means of a second network connection (9b) within the second network domain (2b), a first virtual network connection (4a), which connects the first (6a) and the third (6b) marginal nodes via an intermediate network (3), and a second virtual network connection (4b), which connects the second (7a) and the fourth (7b) marginal nodes via the intermediate network (3). The first network connection (9a), the second network connection (9b), the first virtual network connection (4a) and the second virtual network connection (4b) have a ring topology on which a connection redundancy protocol is implemented.