Packet-switched communication network, having: - a first network that comprises first network nodes (A-E) of the first network that are connected by first data links of the first network, wherein RSTP is executed in the first network nodes (A-E) of the first network as a first network protocol, and - a second network that comprises second network nodes (G-M) of the second network that are connected by second data links of the second network, wherein a second network protocol that is different from RSTP is executed in the second network nodes (G-M) of the second network, wherein, in the communication network: - the two networks (2, 3) are connected to one another via at least two connecting links that each connect at least one first network node (C-E) of the first network and at least one second network node (G-J) of the second network, - both the second network protocol, which is different from RSTP, and RSTP are executed in the second network nodes (G-J) of the second network that are connected to at least one first network node (A-E) of the first network via at least one connecting link, as a result of which said connected second network nodes (G-J) of the second network form an RSTP network within the second network, the network nodes of which are connected to one another by RSTP data links formed by second data links of the second network, wherein an RSTP executing second network node (I, J) of the second network is designed to sense failure of a second data link of the second network, to deactivate an RSTP data link (10, 12) that is connected to the failure of the sensing second network node (I, J) and that contains the failed second data link, and to activate an RSTP data link (12, 7) of the second network node (I, J), which RSTP data link does not contain the failed second data link, on the basis of allocated RSTP path costs, wherein the first data links of the first network, the connecting links and the RSTP data links of the second network have associated RSTP path costs falling in the following order: - RSTP path costs of the connecting links are lower than RSTP path costs of the first data links of the first network, and - RSTP path costs of the RSTP data links of the second network are lower than the RSTP path costs of the connecting links. - a first network that comprises first network nodes (A-E) of the first network that are connected by first data links of the first network, wherein RSTP is executed in the first network nodes (A-E) of the first network as a first network protocol, and - a second network that comprises second network nodes (G-M) of the second network that are connected by second data links of the second network, wherein a second network protocol that is different from RSTP is executed in the second network nodes (G-M) of the second network, wherein, in the communication network: - the two networks (2, 3) are connected to one another via at least two connecting links that each connect at least one first network node (C-E) of the first network and at least one second network node (G-J) of the second network, - both the second network protocol, which is different from RSTP, and RSTP are executed in the second network nodes (G-J) of the second network that are connected to at least one first network node (A-E) of the first network via at least one connecting link, as a result of which said connected second network nodes (G-J) of the second network form an RSTP network within the second network, the network nodes of which are connected to one another by RSTP data links formed by second data links of the second network, - RSTP path costs of the connecting links are lower than RSTP path costs of the first data links of the first network, and - RSTP path costs of the RSTP data links of the second network are lower than the RSTP path costs of the connecting links.