Encontre este post a lo mejor te sirva porque es el mismo error que tu tienes
Cita: The network card comes up and works fine, but when I try:
sysctl -w dev.ath0.rawdev=1
I recieve error: "dev.ath0.rawdev" is an unknown key
Are my old madwifi drivers still installed? Or anyone know the deal?
Edit: Ok scratch that, they drivers were modprobing from update/net yet it was intalling to just net/ directory. I insmod'd them and it worked. So I'll get them squared away. Sorry for the trouble.
Saludos