1. A method, utilizing a computing device operating a network planning for an Ethernet based network having a network topology and a plurality of VLANs to be associated therein wherein the network requires a number of routes therethrough, the method comprising the steps of: determining a set of spanning trees within the network for providing one or more of the number of routes for consideration, each spanning tree comprising a plurality of links; sorting the VLANs into an order based on one or more VLAN criteria for the network topology; mapping each of the sorted VLANs onto the set of spanning trees in order to optimize one or more characteristics relating to the network or any associated feature thereof for the or each combination of spanning tree and VLAN to thereby determine an optimized VLAN tree mapping for each set of spanning trees for each route; selecting a best primary tree for each of the sorted VLANs, based on the order in which the VLANS were sorted, from the set of spanning trees on which the each of the sorted VLANs is mapped for each route in the network topology; analysing possible failures for each link in the best primary tree for each route to derive for each possible failure a backup tree which is optimized in terms of the characteristics and criteria to determine one or more best backup trees to replace the or each best primary tree in the event of a possible failure of the analysed possible failures; translating the best primary tree and the determined one or more best backup trees for each best primary tree for each route in the network into a set of Multiple Spanning Tree Protocol configuration parameters which in combination form a network plan, and outputting information relating to the best primary tree and the determined one or more best backup trees for each best primary tree for each route in the network.