Here is a patch that is a cleaned up version of something I sent
a while back.  This adds the ability to query a device to see if
it is a vlan device by asking for the vlan's parent device.
One can deduce that a querried interface is not a VLAN by looking
at the IOCTL error code.

Patch is against 2.4.22-pre9, compile tested and extracted from a run-time
tested patch.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com