Re: convergence and undoing changes

[Mark Burgess]

> The key here is that for reversions to be effective, they must stay
> in the configuration until it is absolutely sure that all stations
> have applied them. In a very large network, one is likely never
> sure, so one can *never* remove the reversions. This is the principle
> of observability:
>    Once one manages a thing, one must continue to manage that
>    thing in perpetuity.

This is true.