Forrest Discovery scanning for IP subnets should be dynamic within SCCM. Defined susbnets that change in AD, do not update and showt this.
Defined susbnets that change in AD, do not update and showt the new data. Description or the exacts of a defined ip range or ip subnet that are changed in AD, do not show up in SCCM. While re-using or moving IP subnets is not a great idea, it does happen and sometimes happen often.