A method for routing of data packets in a network topology, the method comprising: - receiving, at a source edge router, a data packet from a source host router connected to a source host, said data packet comprising a source IP address of the source host and a destination IP address of a destination host, the data packet being received on an interface of the source edge router identified by a virtual private network identity, VRF-ID; wherein the method further comprises: - extracting, at the source edge router, from a configuration information on said interface of the source edge router, a zone-identity, zone-ID, assigned to a destination edge router to which a destination host router is associated, wherein the destination host router is connected to the destination host, and wherein the configuration information is assigned to the source edge router and the zone-ID assigned to the destination edge router is unique; the destination edge router being located in a zone that is different from a zone of the source edge router; - including, by the source edge router, the zone-ID and the VRF-ID in between Layer 2 and Layer 3 information of the data packet; - sending, by the source edge router, the data packet towards the destination edge router having the assigned zone-ID; wherein sending the data packet includes: determining, from a routing table of the source edge router, whether there is at least one next hop router to which the data packet is to be sent to before reaching the destination edge router having the zone-ID; and that being the case, sending the data packet to the next hop router; and - determining , by the next hop router, if the zone-ID in the received data packet differs from a zone-ID assigned to the next hop router, and that being the case, determining from a routing table of the next hop router, the address of a subsequent next hop router to which the data packet comprising the zone-ID and the VRF-ID is to be forwarded to; and sending the data packet to the subsequent next hop router. - receiving, at a source edge router, a data packet from a source host router connected to a source host, said data packet comprising a source IP address of the source host and a destination IP address of a destination host, the data packet being received on an interface of the source edge router identified by a virtual private network identity, VRF-ID; wherein the method further comprises: - extracting, at the source edge router, from a configuration information on said interface of the source edge router, a zone-identity, zone-ID, assigned to a destination edge router to which a destination host router is associated, wherein the destination host router is connected to the destination host, and wherein the configuration information is assigned to the source edge router and the zone-ID assigned to the destination edge router is unique; the destination edge router being located in a zone that is different from a zone of the source edge router; - including, by the source edge router, the zone-ID and the VRF-ID in between Layer 2 and Layer 3 information of the data packet; - sending, by the source edge router, the data packet towards the destination edge router having the assigned zone-ID; wherein sending the data packet includes: determining, from a routing table of the source edge router, whether there is at least one next hop router to which the data packet is to be sent to before reaching the destination edge router having the zone-ID; and that being the case, sending the data packet to the next hop router; and - determining , by the next hop router, if the zone-ID in the received data packet differs from a zone-ID assigned to the next hop router, and that being the case, determining from a routing table of the next hop router, the address of a subsequent next hop router to which the data packet comprising the zone-ID and the VRF-ID is to be forwarded to; and sending the data packet to the subsequent next hop router. <EOS>