WAN standards typically describe both physical layer delivery methods and data link layer requirements, including physical addressing, flow control, and encapsulation. 廣域網路標準典型地描述實體層的傳送方法和資料鏈結層的需求，包括實體層定址，流量控制和封裝。
When this feature is disabled any packets received that are destined for a subnet that falls within the subnetwork addressing scheme of the router will be discarded. 如果此功能被停用，當路由器收到目的地為特定子網路的封包，而這些子網路正好在路由器的子網定址機制內，則這些封包將被丟棄。
