From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265135AbUGGOTh (ORCPT ); Wed, 7 Jul 2004 10:19:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265146AbUGGOTh (ORCPT ); Wed, 7 Jul 2004 10:19:37 -0400 Received: from ns0.eris.qinetiq.com ([128.98.1.1]:43 "HELO mail.eris.qinetiq.com") by vger.kernel.org with SMTP id S265135AbUGGOTf convert rfc822-to-8bit (ORCPT ); Wed, 7 Jul 2004 10:19:35 -0400 From: Mark Watts Organization: QinetiQ To: linux-kernel@vger.kernel.org Subject: Re: stupied userspace programs or kernel bug ? Date: Wed, 7 Jul 2004 15:15:10 +0100 User-Agent: KMail/1.6.1 Cc: Adam Popik References: In-Reply-To: MIME-Version: 1.0 Content-Disposition: inline Content-Type: Text/Plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Message-Id: <200407071515.10625.m.watts@eris.qinetiq.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > Hello ; > That is a problem: > linux#ifconfig eth0 192.168.1.1 Because you didn't specify a netmask, it defaulted to 255.255.255.0 > linux#ifconfig lo:1 192.168.1.100 netmask 255.255.255.255 up Although you specified a tighter netmask here, the routing table is such that 192.168.1.0/24 is routed out eth0, overriding the fact that 1.100 is on lo:1 I'll bet the kernel responds to the ICMP echo request because it knows it holds the IP for 1.100 so it should respond, yet its outbound routing tells it to respond via eth0. (somone connect me if I'm wrong) This is probably a side effect of having two interfaces on the same subnet, and having the /24 subnet higher up the routing rable than the /32 host. I believe the behaviour you are seeing is 'by design' although the merits of this have been discussed to death in the past (IIRC) Mark. - -- Mark Watts Senior Systems Engineer QinetiQ Trusted Information Management Trusted Solutions and Services group GPG Public Key ID: 455420ED -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFA7AVuBn4EFUVUIO0RAlXpAJ9I1FBUhqDDgV3Tvs53NjSM9BQq9QCeIVeu f4Jzs0L/LlvjOsm8CcMNoJs= =/jLZ -----END PGP SIGNATURE-----