An STP link selection system includes a first and second designated switch devices providing different paths to a root switch device. A non-designated switch device receives a first communication from the first designated switch device identifying a first root path cost for a first link to the first designated switch device and a first designated switch device identifier, and designates the first link as an active link for communications to the root switch device. The non-designated switch device subsequently receives a second communication from the second designated switch device identifying a second root path cost for a second link to the second designated switch device that is equal to the first root path cost, and a second designated switch device identifier that is lower than the first designated switch device identifier. In response, the non-designated switch device designates the second link as a non-active link upon which communications are blocked.