From: michi1@michaelblizek.twilightparadox.com (michi1 at michaelblizek.twilightparadox.com)
To: kernelnewbies@lists.kernelnewbies.org
Subject: packet drop
Date: Thu, 15 May 2014 18:09:53 +0200 [thread overview]
Message-ID: <20140515160953.GB4220@grml> (raw)
In-Reply-To: <CAFat2-iuvnoZyR94Pkxz9K161Ykondgq+_LWe31thXzOrBnmsg@mail.gmail.com>
Hi!
On 09:56 Thu 15 May , Varun Sharma wrote:
> Hi All,
>
> I am sending packet between two back to back connected machine.when I
> use same network (192.168.7.x) packet reach upto NF_IP_LOCAL_IN
> (IPTABLES INPUT) hook.It is accepted.
>
> But when I spoof ip address network(192.168.8.x) it pass
> NF_IP_PRE_ROUTING hook but dropped before NF_IP_LOCAL_IN hook.
>
> case 1:
>
> 192.168.7.12 --> 192.168.7.19 Accepted.
>
> case 2:
>
> 192.168.8.25 --> 192.168.7.19 Dropped.
>
> I didn't get why it dropped ? How network change effect on routing
> inside kernel tcp/ip stack ?
Maybe you have "Reverse Path Filtering" turned on:
http://lartc.org/howto/lartc.kernel.html
Try setting /proc/sys/net/ipv4/conf/*/rp_filter to "0".
-Michi
--
programing a layer 3+4 network protocol for mesh networks
see http://michaelblizek.twilightparadox.com
prev parent reply other threads:[~2014-05-15 16:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-15 4:26 packet drop Varun Sharma
2014-05-15 16:09 ` michi1 at michaelblizek.twilightparadox.com [this message]
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