I have an OpenBSD 3.9 box with two sk(4) devices and an ethernet cable between them (later to be replaced by other equipment). I tried some simple testing as follows:
$ ifconfig sk0 192.168.50.1 $ ifconfig sk1 192.168.50.2 $ ping -I 192.168.50.1 192.168.50.2 $ ping -I 192.168.50.2 192.168.50.1 When I pull the ethernet cable, the ping responses stop, and when I replug it, they resume again, so I'm under the impression (some of) the packets are actually traversing the cable. However, when I run ``tcpdump -i sk0'' (or sk1---they give the same output), I see ``192.168.50.1 > 192.168.50.2: icmp: echo request'' lines cerresponding to the first ping command and ``192.168.50.1 > 192.168.50.2: icmp: echo reply'' lines corresponding to the second ping command, but nothing from 192.168.50.2 to 192.168.50.1. (This output also continues when I unplug the ethernet cable.) My best guess is traffic from sk0 to sk1 is crossing the ethernet cable, but the reverse traffic is being directly routed by the kernel: if I swap the IP assignments, I start seeing only ``192.168.50.2 > 192.168.50.1'' traffic instead. Is my guess correct? If so, is it possible to have OpenBSD route traffic both ways across the ethernet cable? Thanks.
