From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pascal Hambourg Subject: Re: two default routes Date: Mon, 22 Mar 2010 16:47:50 +0100 Message-ID: <4BA79126.1040903@plouf.fr.eu.org> References: <4BA784B2.9030406@plouf.fr.eu.org> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: netfilter-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: netfilter@vger.kernel.org ratheesh k a =E9crit : >=20 > suppose ip 8.8.8.8 is accessible thru gateway 10.232.18.5 and we > configured the linux machine to accept > icmp redirect messages ( if we set NET_IPV4_CONF_ACCEPT_REDIRECTS ) = =2E Do you mean sysctl net.ipv4.conf..accept_redirects ? Note that this settings is ignored (and so are ICMP redirects) when forwarding is enabled, thus when Linux acts as a router. > Linux will send packet to 8.8.8.8 thru 192.168.1.1 as per default > route . The gateway machine ( ip 192.168.1.1 ) will respond back wit= h > icmp redirect . (I think so ) If it is configured to do so. If it runs a Linux kernel, see sysctl net.ipv4.conf..send_redirects. > So our linux machine can use the other route ? Yes, a temporary redirect route to 8.8.8.8 will be created in the routing cache. You can see it with "ip route show cache". Note : This does not seem to be much related to netfilter.