From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Sun,  1 Sep 1996 15:47:46 -0400
From: Russ Cox rsc@research.att.com
Subject: ppp fix for mtu
Topicbox-Message-UUID: 4c28c086-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19960901194746.Gvsdyf2Qt4nR3-LQVvFAcDO4gTuDpYZLSrqlculnaWs@z>

I have (attempted to) fix ppp so that it respects
the remote's wishes as far as MTU is concerned.
There is a boddle on plan9.bell-labs.com in
/cm/cs/who/rsc/ppp.rc and stip.rc.  Use at your
own risk.

ppp.rc needs to be applied in /sys/src/cmd/ppp
and also contains the changes that were in ppp.bod
from forsyth.

stip.rc needs to be applied in /sys/src/9/port
and changes the setip message.  An MTU parameter
is added to the end, and if there is a '-' for
any parameter, it is treated as if it wasn't there.
Thus,
        setip 135.104.3.9 255.255.255.0
is the same as
        setip 135.104.3.9 255.255.255.0 - -

This is used by ppp, which does:
        setip 135.104.3.9 255.255.255.0 - mtu

and lets ipmuxctl figure out what the third
parameter should be.

Russ