Theodore Ts'o writes:
What Linux implemented was specifically what was specified by RFC
3168, no more no less.
What FreeBSD implemented actually works. Which is preferable?
The issue is whether or not intermediate hosts are
justified in dropping packets just because some
bits that were reserved for future use are no longer
zero. I would argue no.
I doubt that arguing that it is someone else's fault will fix the
In fact, while many or most hosts do not support ECN, very few errant
firewalls and/or load balancing boxes were dropping packets that
But if one of them is in front of this site, you won't be able to get to
it from Linux.
Firmware updates have been available for over two years
to fix those firewalls are broken, including no doubt
the ones used by ISOC.
But since ISOC's firewalls have not been updated, you won't be able to
get to their site from Linux.
It's just that the ISOC firewall admins simply haven't had the
wit to upgrade their firewall firmware.
It's just that Linux developers refuse to write code that will allow
communication with sites that don't mean Linux's lofty standards.
Pretty much all of the commercial websites were fixed
a long, long, LONG time ago.
Every site I try to access from FreeBSD is accessible, whether it has
been "fixed" or not.
Do you see the problem? If it's still fuzzy, replace Linux with
Microsoft, and I'm sure that will provoke the usual visceral reaction
and call to arms.