Is it at all possible that ipnat is getting confused while either 
transmitting or receiving packets that the modem is trashing, while the
standard IP stack is simply not getting stumped by the same trashed packets?

Or, looked at slightly differently, maybe ipnat gets confused if the ppp
interface gets corrupted or drops *during* packet transmission/receipt,
whereas the standard IP stack doesn't?

-Avram

----------
>From: "Dr. Bill Studenmund" <wrstuden@loki.stanford.edu>
>To: Roger Fischer <roger@badger1.net>
>Cc: Bruce Anderson <brucea@spacestar.net>, port-mac68k@netbsd.org
>Subject: Re: NAT not passing all characters?
>Date: Wed, Apr 7, 1999, 1:16 AM
>

> On Tue, 6 Apr 1999, Roger Fischer wrote:
>
>> >> <brucea@wavefront.com>
>> >> I figured out what is wrong with my mail.
>> >> The problem is with "+" ASCII 0x2B ( decimal 43) getting intercepted by
the
>> >> modem as AT commands in the IO stream. Without SLIP/PPP escaping "+" the
>> >> modems enter command mode.
>> >> I tested this by sending mail with a valid AT command in the body of the
>> >> message. (turned my speeker on and off)
>>
>> except that the pppd man page specifically says that you can not
>> escape characters with hex values between 0x20 and 0x3f.
>
> I thought Bruce had this problem a year ago.
>
> Roger,
>
> If you are having the problem of "+ + +", w/o the spaces, crashing your
> modem, then you need to sue your modem manufacturer - it's not Hayes
> compatable. :-)
>
> But I thought your problem was that, using NAT you had problems, not using
> NAT (and I assumed the same modem & ISP) you didn't. ??
>
> take care,
>
> Bill
>