An important element in beating back network chaos is a well-ordered spanning-tree. Spanning-tree was mostly ignored and/or disabled (!) by my predecessors. Much unloved, spanning-tree is one of those protocols that networking folks are prone to turn their backs on, looking at it from a distance with a jaundiced eye. ”If I leave it alone, it can’t hurt me, ” seems to be the mantra, right up there with, “Don’t ask, don’t tell,” and “Let sleeping dogs lie.”