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From: Pascal Hambourg <pascal.mail@plouf.fr.eu.org>
To: netfilter@vger.kernel.org
Subject: Re: two default routes
Date: Mon, 22 Mar 2010 16:47:50 +0100	[thread overview]
Message-ID: <4BA79126.1040903@plouf.fr.eu.org> (raw)
In-Reply-To: <cfeab66d1003220805t41853241jddfa85b54e745315@mail.gmail.com>

ratheesh k a écrit :
> 
> 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 )  .

Do you mean sysctl net.ipv4.conf.<interface>.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 with
> icmp redirect . (I think so )

If it is configured to do so. If it runs a Linux kernel, see sysctl
net.ipv4.conf.<interface>.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.

  reply	other threads:[~2010-03-22 15:47 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-22 10:35 two default routes ratheesh k
2010-03-22 12:48 ` Richard Horton
2010-03-22 14:54 ` Pascal Hambourg
2010-03-22 15:05   ` ratheesh k
2010-03-22 15:47     ` Pascal Hambourg [this message]
2010-03-22 15:56       ` ratheesh k
2010-03-22 16:53         ` Pascal Hambourg
2010-03-22 16:21       ` Richard Horton
2010-03-22 16:26         ` Jan Engelhardt

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