Subject: Re: default values for IPv4
To: Jun-ichiro itojun Hagino <>
From: Thor Lancelot Simon <>
List: tech-net
Date: 06/12/2002 10:14:24
On Wed, Jun 12, 2002 at 07:24:33PM +0900, Jun-ichiro itojun Hagino wrote:
> >Okay, so, I'm trying to understand what you're saying here -- and failing
> >miserably.
> >What, exactly, does changing these two defaults have to do with "backward
> >compatibility"?
> 	or, least surprise.
> 	there are multiple ways in doing this.
> 	- change kernel default value.  some may surprise, but kernel upgrade
> 	  alone will take care of everything.

I think this is the appropriate change.  Historically, as we've improved
our TCP, we have gradually turned on the new features by default after some 
time has passed to demonstrate that they actually work as expected.  Path
MTU was off because we didn't have blackhole detection and thus knew there
were problems.  Since you added blackhole detection, I don't think there's
any reason for Path MTU to be off by default (Jason?  Kevin?).