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Re: sysctl should disable ECN by default



On Sun, Sep 02, 2001 at 12:56:18AM +0200, Tomas Pospisek wrote:
> 
> Zitiere Eduard Bloch <edi@gmx.de>:
> 
> > Neil Spring wrote on Sat Sep 01, 2001 um 12:34:40PM:
> > 
> > > being turned off behind my back.  ECN doesn't need any
> > > more inertia slowing its deployment.  It's already an 
> > > experimental, off by default, addition to the kernel.
> > 
> > Why do many people think that it is OFF by default?
> > The fact is, it is ON (see kernel docs) and it breaks with many sites.
> > We could live long without this experimental feature, so why _force_
> > the users to use the feature now and make a stable distribution with
> > limited networking ability?
> 
> Incidentaly I'd today filled a *critical* bugreport against
> kernel-image-2.4.8 just because of that.
> 
> It's not only *sites* that do not work with ECN. It's also *routers*. That
> means if you have *one* router between you and your destination, that does not
> support ECN, then you'll get *very* strange behaveour like hanging TCP
> connections that somehow get halfway through but do hang never the less while
> ping works. Please check my bugreport #110862. And amongst the broken equipment
> are f.ex. (older?) Zyxel ISDN routers which are *very* popular.

FYI,

   Zyxel 681 SDSL-Router breaks ECN by stripping 0x80 (ECN Cwnd Reduced) but not 0x40 (ECN Echo) (TOS bits) on all SYN
   packets. This is the last official firmware. A beta firmware is available internally which fixes this issue: (ZyXEL
   firmware v2.50(T.05)b6 | 03/28/2001)

-- 
Eric VAN BUGGENHAUT     "Oh My God! They killed init! You Bastards!"
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