De um rascunho expirado da IETF " Redesenho de 240/4 de" Uso futuro "para" Particular Use ""
Apple OSX has been confirmed to support the use of 240.0.0.0/4 as
unicast address space. Changes have been incorporated into
recent
versions of Sun Solaris and have been submitted for inclusion in
the Linux kernel tree. No plans have been announced for
modifications to any version of Microsoft Windows, in part
because
of uncertainty over how to perform 6-to-4 tunneling in the
absence
of a definitive statement on whether 240.0.0.0/4 is "public" or
"private" space.
Portanto, a maioria dos sistemas operacionais não suportará esse intervalo de endereços, mesmo que você possa forçar um dispositivo a usá-lo.