This object toggles Poison Reverse, a RIP enhancement that advertises routes back toward the interface they were learned from with an infinite metric rather than suppressing them outright. It matters because poison reverse speeds up convergence after a link failure compared to plain split horizon, at the cost of slightly larger RIP updates. For instance, a network operator enables csRipIfConfPoisonReverse on a partial-mesh Frame Relay virtual interface to make routing loops resolve faster when one of the point-to-point paths goes down.