I have been writing a CNR extension to override my BAC installation under specific conditions for the boot-file. I was having some issues where DOCSIS 1.1 and higher modems where they are not seeing my new file that was modified on the boot-file (option 67) then I realized after debugging on a packet level that BAC is also setting "dhcp-option-overload" sub-option "file" and that is being preferred. I need to know what "$response put" statement I need to modify that sub-option. My CNR Extension is in TCL if not obvious.
Corey
Been a while since I did TCL extensions with CNR but I think it is just
$response put file "whatever your filename is"
derived from Here
However the overload concerns me, there is only so much room in a dhcp packet for options I wanna say 128 bytes, but don't quote me on it, after that it starts using oft unused bootp fields and overloads them with overflow option data. So say you had 135 bytes of optionsit would put 127 in the normal place and then use the last byte to signal the client that some of the overflow is in either the sfile or server fields. The client would combine all of the data from both fields and then decode it. refer to the RFC for DHCP for more information.
Question though, why do you need access to it at the extension level? I would think that this would be something you added when you added the client in?
"Question though, why do you need access to it at the extension level?"
The reason is simple. BAC fills out a default class of service globally for unknown modems but I want to be able to change that default class of service for a specific giaddr. As for using $response put file "whatever you filename is" it does not see that as a variable.
Corey