Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263436AbUCYRpP (ORCPT ); Thu, 25 Mar 2004 12:45:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263455AbUCYRpP (ORCPT ); Thu, 25 Mar 2004 12:45:15 -0500 Received: from chaos.analogic.com ([204.178.40.224]:30080 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S263436AbUCYRpF (ORCPT ); Thu, 25 Mar 2004 12:45:05 -0500 Date: Thu, 25 Mar 2004 12:45:20 -0500 (EST) From: "Richard B. Johnson" X-X-Sender: root@chaos Reply-To: root@chaos.analogic.com To: Marco Berizzi cc: Linux kernel Subject: Re: proxy arp behaviour In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1588 Lines: 52 On Thu, 25 Mar 2004, Marco Berizzi wrote: > Hello everybody, > > I would like some info about proxy arp behaviour. > I have a firewall linux running kernel 2.4.25 > with 3 NIC. Proxy arp is enabled on two of them > (eth0 and eth1). > > eth1 configuration is here: > > ifconfig eth1 10.77.77.1 broadcast 10.77.77.3 netmask 255.255.255.252 > ip route del 10.77.77.0/30 dev eth1 > ip route add 172.17.1.0/24 dev eth1 > > echo 1 > /proc/sys/net/ipv4/conf/eth1/proxy_arp > > Hosts connected to eth1 are all 172.17.1.0/24. > The linux box is now replying to arp requests > that are sent by 172.17.1.0/24 hosts on the eth1 > network segment. Is this because ip on eth1 is > 10.77.77.1? > > I think that linux should not reply to arp request > for 172.17.1.0/24 because of: > > ip route add 172.17.1.0/24 dev eth1 > > Is this a bug? This problem comes up periodically and when it does there results in a bunch of noise to show that "Linux works perfectly...", but never with any resolution. What needs to be answered by persons who know the network code is how one "connects" a particular response to a particular device. This has become a FAQ and needs to have some written documentation somewhere. Cheers, Dick Johnson Penguin : Linux version 2.4.24 on an i686 machine (797.90 BogoMips). Note 96.31% of all statistics are fiction. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/