Applications that break when not using /64

Tue Jun 17 22:02:32 UTC 2014

On Tue, Jun 17, 2014 at 2:13 PM, Jeroen Massar <jeroen at massar.ch> wrote:

> On 2014-06-17 22:36, Grzegorz Janoszka wrote:
> > On 2014-06-17 22:13, David Conrad wrote:
> >> On Jun 17, 2014, at 12:55 PM, Grzegorz Janoszka <Grzegorz at Janoszka.pl>
> >> wrote:
> >>> There are still applications that break with subnet smaller than /64,
> >>> so all VPS providers probably have to use /64 addressing.
> >>
> >> Wouldn't that argue for /64s?
> >
> > /64 netmask, but not /64 for a customer. There are application which
> > break if provided with /80 or /120, but I am not aware of an application
> > requesting /64 for itself.
>
> Except for SLAAC that requires a /64 due to it using EUI-48 to make up
> the address, which "applications" are these, as those applications are
> broken by design.
>
> An application (unless it is a protocol like SLAAC or something else
> similarly low-level) does not need to know about prefix sizes nor
> routing tables.
>
> Thus, can you please identify these applications so that we can hammer
> on the developers of those applications and fix that problem?
>

I tried to configure my FreeBSD box at home to
use a /120 subnet mask.  It consistently crashed
with a kernel panic.  I eventually gave up and just
configured it with a /64.  Not really an application
per se, but since the OS died, I couldn't actually
tell if the applications were happy or not.  :(

Matt