*BSD News Article 70633


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.rmit.EDU.AU!news.unimelb.EDU.AU!munnari.OZ.AU!news.hawaii.edu!news.uoregon.edu!vixen.cso.uiuc.edu!newsfeed.internetmci.com!solaris.cc.vt.edu!news.mathworks.com!fu-berlin.de!cs.tu-berlin.de!uni-erlangen.de!news.tu-chemnitz.de!irz401!uriah.heep!news
From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: PPP on FreeBSD v2.1.0
Date: 10 Jun 1996 18:29:30 GMT
Organization: Private BSD site, Dresden
Lines: 40
Message-ID: <4phpia$4n0@uriah.heep.sax.de>
References: <4p56p5$8js@azure.acsu.buffalo.edu>
  <31B9F12B.7909@idt.liberty.com>
  <Pine.NEB.3.93.960609234137.1774C-100000@tomqnx.tomqnx.com>
Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch)
NNTP-Posting-Host: localhost.heep.sax.de
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Newsreader: knews 0.9.6
X-Phone: +49-351-2012 669
X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F  93 21 E0 7D F9 12 D6 4E

Tom Torrance at home <tom@tomqnx.com> wrote:

> I had similar problems with ppp as well using tun0 to communicate with a
> Shiva LAN Rover.  Inspecting /var/log/ppp.log, I saw that it was
> complaining about an unknown protocol.

The unknown protocol should not be the problem.  It should be silently
disabled, and as long as the protocol wasn't a substantial one (like
IPCP -- the IP control protocol), it should continue.

However, iijppp has a bug where it falls flat on the face when pred1
compression is not disabled, but the remote peer doesn't speak pred1
CCP.  Both peers still negotiate CCP, but cannot agree on a common
compression protocol to use.  Alas, iijppp still continues to send
pred1-compressed data packets later, in the assumption that the
existance of a working CCP alone would justify this. :-/

This got very obvious after upgrading a FreeBSD PPP server to FreeBSD
post-2.1, where the pppd does also speak CCP (but only knows about BSD
compression).  The net effect was the same as you described, and since
i was unable to find the bug in iijppp i picked the lazy route and
hacked pppd to shutdown the CCP layer if no agreement on the
compression protocol could be negotiated.  (CCP is of no use in this
case anyway.)  This did at least insure that iijppp and pppd could
communicate together without special tweaks, but iijppp remains to be
the buggy one.

In short, since _you_ can decide to manually disable pred1 compression
on your side, _this_ should do the trick for you.

(Btw., the apparent effect of the above bug is that you can initially
send about one or two ping packets across the wire, before everything
starts to stall.)

-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)