* packet drop
@ 2014-05-15 4:26 Varun Sharma
2014-05-15 16:09 ` michi1 at michaelblizek.twilightparadox.com
0 siblings, 1 reply; 2+ messages in thread
From: Varun Sharma @ 2014-05-15 4:26 UTC (permalink / raw)
To: kernelnewbies
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 ?
Regards
Varun
^ permalink raw reply [flat|nested] 2+ messages in thread
* packet drop
2014-05-15 4:26 packet drop Varun Sharma
@ 2014-05-15 16:09 ` michi1 at michaelblizek.twilightparadox.com
0 siblings, 0 replies; 2+ messages in thread
From: michi1 at michaelblizek.twilightparadox.com @ 2014-05-15 16:09 UTC (permalink / raw)
To: kernelnewbies
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
^ permalink raw reply [flat|nested] 2+ messages in thread
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2014-05-15 4:26 packet drop Varun Sharma
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