From owner-freebsd-questions Fri Jul 3 08:12:21 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA10861 for freebsd-questions-outgoing; Fri, 3 Jul 1998 08:12:21 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from alcatel.fr (ns.rfs.tm.fr [194.133.58.131]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA10853 for ; Fri, 3 Jul 1998 08:12:17 -0700 (PDT) (envelope-from THIERRY.HERBELOT@telspace.alcatel.fr) From: THIERRY.HERBELOT@telspace.alcatel.fr Received: from alcatel.fr (gatekeeper-ssn.alcatel.fr [155.132.180.244]) by mailgate.alcatel.fr (ALCANET/SMTP.9.9.9) with ESMTP id OAA28623; Fri, 3 Jul 1998 14:57:52 +0200 Received: from aifhs1.alcatel.fr (aifhs1.alcatel.fr [155.132.180.86]) by aifhs2.alcatel.fr (ALCANET/SMTP2) with ESMTP id OAA09576; Fri, 3 Jul 1998 14:46:26 +0200 (MET DST) Received: from aifhs2.alcatel.fr (localhost [127.0.0.1]) by aifhs1.alcatel.fr (8.8.8/8.8.8) with ESMTP id OAA10707; Fri, 3 Jul 1998 14:49:27 +0200 (MET DST) Received: from lune.telspace.alcatel.fr (lune.telspace.alcatel.fr [155.132.144.65]) by aifhs2.alcatel.fr (ALCANET/SMTP2) with ESMTP id OAA08814; Fri, 3 Jul 1998 14:44:41 +0200 (MET DST) Received: from telss1 (telss1.telspace.alcatel.fr [155.132.51.4]) by lune.telspace.alcatel.fr (8.7.6/8.7.3) with SMTP id OAA04775; Fri, 3 Jul 1998 14:51:44 +0200 (MET DST) Received: from telspace.alcatel.fr by telss1 (4.1/SMI-4.1) id AA23938; Fri, 3 Jul 98 14:40:40 +0200 Received: from localhost by telspace.alcatel.fr with SMTP (1.40.112.12/16.2) id AA112179384; Fri, 3 Jul 1998 14:36:24 +0200 X-Openmail-Hops: 1 Date: Fri, 3 Jul 98 14:36:11 +0200 Message-Id: In-Reply-To: <359CC63B.1EBE5AF5@tdx.co.uk> Subject: =?ISO-8859-1?Q?R=E9p_:_Re:_tcpdump_on_a_dial-in_PPP_connection_??= Mime-Version: 1.0 To: kpielorz@tdx.co.uk, freebsd-questions@FreeBSD.ORG Content-Type: text/plain; charset=ISO-8859-1; name="Re:" Content-Disposition: inline; filename="Re:" Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by hub.freebsd.org id IAA10856 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hi I **have** bpf configured in my kernel and the bpf? devices also exist. What i'm looking for is a way to start tcpdump when ppp opens the link (ppp itself being started by mgetty upon recognition of a PPP negociation). I can't have tcpdump listening on tun0 all the time, because tun0 only exists when ppp is called by mgetty : If I start tcpdump without waiting for PPP to be on : # tcpdump -i tun0 tcpdump: tun0: Network is down I've got the following in /etc/ppp/ppp.linkup : MYADDR: delete 0 add 0 0 HISADDR !bg tcpdump -l -i tun0 >> /tmp/tun0 but /tmp/tun0 stays empty I have also modified the permissions of tcpdump and the bpf devices to allow execution by anyone (big security hole - I know ...). I'm stuck !!! ____________________________ Séparateur Réponse ________________________________ Objet : Re: tcpdump on a dial-in PPP connection ? Auteur : kpielorz@tdx.co.uk Date : 03/07/98 13:53 THIERRY.HERBELOT@telspace.alcatel.fr wrote: > > Hello, > > I would like to see what packets are exchanged on a dialin PPP link > > I manage my modem with mgetty (as indicated in the handbook) - on an > incoming call, all goes well : ppp is established, .... [snip] > > Any ideas ? Try configuring your kernel to use bpfilters - i.e. add pseudo-device bpfilter 2 To your kernel, recompile it, install it, restart the system... When your connected via PPP you should be able to do something like: tcpdump -i tun0 (I think bpf's work with tun interfaces ;-) Regards, Karl To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message