Hi, On Wed, Nov 09, 2022 at 07:21:44AM -0500, Greg Troxel wrote: > Looking at if_tun.c, I see DLT_NULL. This should have the same ability > to write. I have forgotten the details of how tun encodes AF when > transmitting, but I know you can have v4 or v6 inside, and tcpdump works > now. so obviously I must be missing something.
On the user side of if_tun (not bpf), a 2-byte value consisting of htonl(AF_INET6) / htonl(AF_INET) is prepended before the actual packet. gert -- "If was one thing all people took for granted, was conviction that if you feed honest figures into a computer, honest figures come out. Never doubted it myself till I met a computer with a sense of humor." Robert A. Heinlein, The Moon is a Harsh Mistress Gert Doering - Munich, Germany g...@greenie.muc.de