Hello All, Summary: === If a userspace program has a well crafted packet (ethernet or IPv4 or other protocol packet), is there a way for it to send the packet to kernel's network interface, simulating the behavior that the packet ingress'ed on that interface? Is this possible? Detailed Problem Description: === I am working on packet sampling feature (sFlow) on OpenSwitch (www.openswitch.net) Network OS. Currently, this OS is supported on few Accton switches that has Broadcom's Trident2 chipset. When we enable packet sampling, the sampled packets are sent to a userspace program, by passing the kernel network stack. This is a problem if the packet was supposed to go up the network stack. I am investigating options to re-send the packet back to kernel interface on which packet arrived on the switch. Hence this question. A colleague suggested looking at Tuntap interfaces. I did a quick research and it did not appear that can be done. Any suggestions or pointers for further reading will be very helpful. Thanks.