Subject: Re: dumping options TCP_COMPAT_42
To: None <>
From: William Allen Simpson <>
List: tech-net
Date: 11/11/2006 20:25:38
Perry E. Metzger wrote:
> 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.
With all due respect to jhawk and others, I think that Perry is correct,
even though Perry is doing a bit of proof by assertion....

15 years ago, we usually had to hack in 4.2 compatibility, because there
were old machines still lying around.  They already couldn't communicate
with many systems on the Internet, but sometimes were needed over local
links (in 1991, I donated a 486 to the local Arbornet community BBS to
serve as a front end).

10 years ago, I'm reasonably sure that every such system I've ever known
was long retired.  Even poor community and school systems are retired
that cannot get spare parts....  Nothing lasts forever.

In general, I'm in favor of retiring buggy systems and deprecating bad
practices with prejudice.

OTOH, perhaps NetBSD would be useful in a museum to communicate with
ancient systems as a demonstration?  Is that a target audience?