I'm using debian, linux kernel 18.104.22.168. I have one computer with one NIC, connected to a switch.
I want to bypass the internal check for network routing, so the network traffic is sent through the wire and back if I send data to myself.
For example if I set my IP to 192.168.1.1, and have some client and a server on the same machine sending to 192.168.1.1, I want that data to go out to the switch, then back.
I was hoping I could just set accept_local to 1, but that did not work.
If this is not possible a solution involving multicast will also be accepted. For example, I've tried sending multicast with the IP_MULTICAST_LOOP flag to 0 (in the client application), which did remove the local kernel connection, but instead I got no connection when the packets came back.