On Wed, 24 Jul 2002, Brian E Carpenter wrote:
Franck,
ISOC knows about this, but you actually need to contact ISOC's ISP.
But frankly it's a quixotic mission; SMTP mailers that break when they
find a non-ECN-tolerant SMTP peer are likely to encounter trouble for
some years to come.
The issue here is that there is a MAY in RFC 3168 that IMHO should
be a SHOULD. That's the first MAY in section 6.1.1.1. If your ECN
code implemented that MAY, you would not have seen a problem.
That "hack" was never added to the Linux implementation (dont think you
will *ever* see it as part of the Linux TCP code). I am glad we did
that: almost all the net sites that had anything to do with fixing their
broken boxes to date have had admins who got emails from someone using
Linux who told them their site was broken. I dont know what Franck uses
but i am willing to bet it is Linux.
On the issue of "I should be allowed to block whatever bits i want", i
would say if you block ECN you will hear from some rabid Linux user ;->
On a serious note, you can block whatever you want but you should be able
to do so on a policy basis: Most of the broken boxen dont provide the
admin the option to allow ECN bits (instead hard-coded to drop). And if
you had the option and choose and still decide to drop, its almost as
helpful as blocking all ICMP packets.
cheers,
jamal