This read-write setting selects which loop-prevention technique RIPng uses when it would otherwise advertise a route back out the interface it was learned on, defaulting to split-horizon. Choosing split-horizon(2) simply withholds a learned route from being re-advertised on its source interface, while poison-reverse(3) instead advertises it back with a metric of 16 (unreachable) for faster loop detection at the cost of more update traffic; no-horizon(1) disables this suppression entirely. For example, on a network prone to route flapping, an admin might switch swRIPngMethod from split-horizon(2) to poison-reverse(3) to speed up convergence when a route becomes unreachable.