Use of alternate ports in spanning tree configured bridged virtual local area networks

An improvement to the logic for the use of communication links in data networks that require loop-free forwarding of data frames provides for the use of links identified as alternate, or unused, by spanning tree protocols. While imposing no constraints on the locations of communicating stations in the network that can use the alternate links and requiring neither additional protocol between network devices nor awareness by all devices that alternate links are to be used, the improvement provides the benefits of multiple spanning trees in common network configurations while requiring protocol to compute only a single spanning tree and the benefit of additional network scaling where a number of trees are computed. The improvement is applicable to the Bridged Local Area Networks and the spanning tree protocols specified in IEEE Standards 802.1D and 802.1Q and their amendments and revisions.