Re: 240/4

On Thu, Oct 18, 2007 at 11:00:42PM +0100, michael.dillonbt.com
wrote:
> 
> > why on earth would you want to go and hack this
stuff together,  
> > knowing that it WILL NEVER WORK
> 
> Because I have read reports from people whose technical
expertise I
> trust. They modified the TCP/IP code of Linux and
FreeBSD and were able
> to freely use 240/4 address space to communicate
between machines. This
> means that IT WILL WORK.
> 
> The reports stated that the code patch was simple
because it involved
> simply removing a line of code that disallowed 240/4
addresses.

Actually, to do the job right, you have to change a handful
of conditionals
in about five different files in the Linxux kernel: in.h
(really just
cleanup to remove unused macros), devinet.c, fib_frontend.c,
ipconfig.c,
and route.c.

Attached are the diffs for a 2.6 kernel (implemented and
tested on an Ubuntu
7.04 system) and for a 2.4 kernel (implemented and tested on
a Linksys
WRT45GL running OpenWRT whiterussian 0.9).

As mentioned in an earlier message, Mac OSX, at least the
version that came
with a Powerbook G4 that I have, will accept a 240/4 address
without any
modifications - I used it to test the Linux patches. There
does appear to be
a one line change needed to FreeBSD and/or OSX for it to act
as a router.

Have fun.

	--Vince