The PACKET_RX_PUMP_BACK socket options allows to immediately pump packets sent through PF_PACKET back into the network stack via dev_forward_skb() instead of submitting them to the device driver using deve_queue_xmit(). This feature might be useful to load the network stack with a lot of packets, similar to pktgen. Enable the setting using: int one = 1; setsockopt(fd, SOL_PACKET, PACKET_RX_PUMP_BACK, &one, sizeof(one)); By default, PACKET_RX_PUMP_BACK is disabled and needs to be explicitly enabled on PF_PACKET sockets. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Tobias Klauser <tklauser@distanz.ch>