Subject: Re: kern/9085: enabling RFC1323 support causes some TCP connections
To: Kevin Lahey <kml@logictier.com>
From: David Brownlee <abs@netbsd.org>
List: tech-net
Date: 01/07/2000 14:53:54
On Thu, 6 Jan 2000, Kevin Lahey wrote:
> > Does it make sense for NetBSD to default to RFC1323 off, or
> > maybe be able to enable RFC1323 on a per interface basis?
>
> Where do you draw the line? Should we force all 10/100 interfaces
> to default to 10Mb because some Cisco switches fail to autonegotiate
> the rate? If we turn off every interesting feature because it might
> hurt someone, somewhere, then we're gonna wind up with not much left...
>
Its a case by case evaluation - defaulting to RFC1323 off will
not hurt those who could gain from it by much, while defaulting to
on is known to cause interoperability problems between NetBSD and
other systems - and that makes NetBSD look bad.
Defaulting 10/100 to 10 gives real pain, particularly to those on
100mbit hubs :)
Another example is defaulting to PIIDE DMA - its known to cause
some problems but quirk tables and fallback code can handle most
of them, and its a noticible win when enabled.
If we default to it on, we need to loudly document how to disable
it. I still think we should be able to set it on a per interface
basis, and default to off low bandwidth interfaces.
How you tell a low bandwidth interface is another matter -
picking ppp/slip/strip would get it right most of the time.
David/absolute