In article <51c8a7be05041217453244f225@xxxxxxxxxxxxxx> you wrote: > I need an explanation of what exactly the 'link encap' field returned > by ifconfig means in relationship to an interface. Information about > how to change it and where it comes from would be a tremendous help. It returns the hardware family of the Interface. See: if (ioctl(skfd, SIOCGIFHWADDR, &ifr) < 0) memset(ife->hwaddr, 0, 32); else memcpy(ife->hwaddr, ifr.ifr_hwaddr.sa_data, 8); ife->type = ifr.ifr_hwaddr.sa_family; Normally you can't change it. Or only in some limited way (different ethernet oncoding styles). In case of tun interfaces it is IMHO changed by attaching it. Normally in tun-mode the device is set up as PPP, in TAP mode it is set up as Ethernet. In the unspec case I guess it is set up wrong, and this ImHO means the user mode program is not matching the kernel version (i.e. expecting another ioctl or device). There is also a tunctl command, not sure if it helps you. Greetings Bernd - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html