Subject: Re: dumping options TCP_COMPAT_42
To: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
From: Perry E. Metzger <>
List: tech-net
Date: 11/11/2006 11:10:29
Hauke Fath <hauke@Espresso.Rhein-Neckar.DE> writes:
> At 11:43 Uhr +0100 11.11.2006, Havard Eidnes wrote:
>>So, what, exactly, are the technical reasons you want to remove
>>the option and the associated few lines of code?
> Seconded.
> Others may know more, but ISTR that the option is relevant for on-the-wire
> interoperability with 4.2BSD derived legacy OSes.

No, it really isn't. Everyone fixed these bugs decades ago -- and I
mean *decades*. There are fully grown adults who were born after these
bugs were fixed. You are going to be very very hard pressed to find a
host that still has them.

You seem to believe there are pure 4.2 stacks still out there, but
there aren't. If you had such a stack, it couldn't communicate over
the internet. Hell, it wouldn't even have congestion avoidance. No has
had such a stack in production code for a very, very long time.

If a machine had said bugs, it would be impossible for any modern
machine to speak to it anyway. First, no one using NetBSD actually
turns on the option. Second, no similar support is present in MacOS,
Windows or any other modern Unix. There wouldn't be any boxes for the
machine to speak to.

If someone can stand up and say "I have had a reason to turn this flag
on in the last ten years", I'd be rather astonished.