Subject: Re: ISA ix* and/or IPNAT problem
To: Brian Grayson \(home\) <>
From: Manuel Bouyer <>
List: current-users
Date: 02/26/2001 19:41:13
On Sun, Feb 25, 2001 at 08:35:51PM -0600, Brian Grayson (home) wrote:
>   My main computer/gateway has ix0, ix1, and vr0 interfaces.  With the cable
> modem on vr0, things work great w.r.t. NAT on my home subnet.  If I connect
> ix1 to the cable modem, and restart things, ipnat works  r e a l l y 
> s l o w.  Like seconds/minutes between some keystrokes in a telnet
> session.
>   I know the ix* cards aren't exactly modern, but I know they can keep
> up with 180KB/s local downloads, and the CPU can obviously keep up with NAT
> when I use a different interface.  As another experiment (actually, this was
> the first one), I tried setting up another machine as my gateway -- it has ix0
> and ix1 only.  NAT didn't work very well on ix1 there either (same
> slowness symptoms).
>   BTW, I did remember to change my NAT rules in /etc/ipnat.conf when I
> changed the interface.  Are there any other common gotchas?  It almost
> seems like there's some sort of timeout that every single packet is
> experiencing.

This looks like a problem which has been reported by mac68k users: some
mac ethernet interfaces works very slowly with cable modems, when they work
fine on local network. The same hardware works fine under linux with the
cable modem.

Manuel Bouyer, LIP6, Universite Paris VI.