From owner-freebsd-hackers@FreeBSD.ORG Mon Nov 29 21:21:30 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BF9C116A4D6 for ; Mon, 29 Nov 2004 21:21:30 +0000 (GMT) Received: from rproxy.gmail.com (rproxy.gmail.com [64.233.170.207]) by mx1.FreeBSD.org (Postfix) with ESMTP id 47DB843D49 for ; Mon, 29 Nov 2004 21:21:30 +0000 (GMT) (envelope-from dr.clau@gmail.com) Received: by rproxy.gmail.com with SMTP id a36so445145rnf for ; Mon, 29 Nov 2004 13:21:28 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:return-path:message-id:disposition-notification-to:date:from:user-agent:x-accept-language:mime-version:to:subject:references:in-reply-to:x-enigmail-version:x-enigmail-supports:content-type; b=ezTbVQzOgkW6a+RqvQsjNsIVjtr+O+zuavpLkDPqNfFCaHwKpbE6tDXwJs2vFygmem0bxHhXVaD0xoykU1uMMzfYMXd7hQdgDU1D815PUrHz6FsWLNM4H5YxBDdNg0Bg7GNbw9wwnBzdhfhKVJ/bXVsU1wNwK3vD8M079cAUNcg= Received: by 10.39.3.56 with SMTP id f56mr115907rni; Mon, 29 Nov 2004 13:21:28 -0800 (PST) Received: from ?82.79.29.15? ([82.79.29.15]) by smtp.gmail.com with ESMTP id 64sm9133rna; Mon, 29 Nov 2004 13:21:28 -0800 (PST) Message-ID: <41AB9272.4060107@gmail.com> Date: Mon, 29 Nov 2004 23:19:46 +0200 From: Claudiu Dragalia-Paraipan User-Agent: Mozilla Thunderbird 0.9 (X11/20041125) X-Accept-Language: en-us, en MIME-Version: 1.0 To: hackers@freebsd.org References: <41AA0043.5070109@gmail.com> <20041129185152.GF804@cirb503493.alcatel.com.au> In-Reply-To: <20041129185152.GF804@cirb503493.alcatel.com.au> X-Enigmail-Version: 0.89.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigF3663AF9564B971612035DD7" Subject: Re: ssh & select() problem on 5.3 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Nov 2004 21:21:31 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF3663AF9564B971612035DD7 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Peter Jeremy wrote: > On Sun, 2004-Nov-28 18:43:47 +0200, Claudiu Dragalia-Paraipan wrote: > >>Since the problem occurs only when I connect to the firewall or to a >>server behind it, I started to suspect a hardware failure. Could a >>network card cause such problems ? > > > A couple of people have mentioned path-MTU problems. I've also bumped > into this problem when playing with VLANs where one end of the VLAN > trunk doesn't support long frames - an oversize packet will get ignored > by the receiver without any error being returned. > It seems that packets of size more then 1478 are dropped somewhere, but not on the FreeBSD Firewall. The problem seems to be that it never receives a ICMP "fragmentation needed but DF set". Unfortunately I have control only over the firewall and what's behind it. Next after the firewall (towards internet) there are a switch and a Cisco router. I asked about the settings of this two, and it seems that the switch is used for VLANs, and the Cisco for making a tunnel over fiber channel with the next hop. I have too few information about this at the moment, but I am almost certain that the problems are occuring because of the Cisco router. I did a traceroute from the firewall to outside, and big packets always stop on Cisco router. A traceroute from outside to the firewall always stops at the hop exactly before the cisco router I am talking about, which I suppose is the other end of this tunnel. -- Claudiu Dragalina-Paraipan dr.clau@gmail.com --------------enigF3663AF9564B971612035DD7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (FreeBSD) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFBq5Jzm0FWxb+swkQRAm97AJwLSNpscpuZIiMapKCGbLBi8HAgwQCffMiB TfQEovXNaSr08cuzkt9EbA0= =eUHm -----END PGP SIGNATURE----- --------------enigF3663AF9564B971612035DD7--