Counts packets explicitly rejected, dropped with a notification sent back, arriving inbound on the specific interface in this row. Isolated to one interface, a rising count here is a strong, location-specific indicator of active scanning or probing hitting exactly that link, distinct from the gateway-wide fwRejected figure that wouldn't tell you which physical connection is under probing. Example: fwRejectPcktsIn climbing sharply and specifically on the external interface, while internal interfaces stay flat, confirms the probing traffic is arriving from the internet side rather than from inside the network.