Enable CAP mode packet interface

modulename: capmode.ko


Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>ARCnet support
└─>Enable CAP mode packet interface
In linux kernel since version 2.6.12  
ARCnet "cap mode" packet encapsulation. Used to get the hardware
acknowledge back to userspace. After the initial protocol byte every
packet is stuffed with an extra 4 byte "cookie" which doesn't
actually appear on the network. After transmit the driver will send
back a packet with protocol byte 0 containing the status of the
0=no hardware acknowledge
1=excessive nak
2=transmission accepted by the receiver hardware

Received packets are also stuffed with the extra 4 bytes but it will
be random data.

Cap only listens to protocol 1-8.

source code: