Re: sysctl should disable ECN by default
On Wed, 5 Sep 2001, Eric Van Buggenhaut wrote:
> On Sun, Sep 02, 2001 at 12:56:18AM +0200, Tomas Pospisek wrote:
> >
> > 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)
So it's not only old routers. It's also new ones. Zyxel didn't get it.
But until this day Debian didn't get it either.
Whoever owns a Zyxel router that has this bug will be into troubles
with Debian unless s/he's a netwoking nerd that knows about ECN. Go
figure.
And while we're at it - if you happen to stumble accross a firmware-fix
for the Zyxel Prestige 2864i please point me to it. Because untill I fix
that, one of our customers will be runing a broken network.
*t
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Tomas Pospisek
SourcePole - Linux & Open Source Solutions
http://sourcepole.ch
Elestastrasse 18, 7310 Bad Ragaz, Switzerland
Tel: +41 (81) 330 77 11
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