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* Packets stops traversing after nat PREROUTING
@ 2010-04-14  8:30 Oguz Yilmaz
  2010-04-14  9:59 ` Jan Engelhardt
  0 siblings, 1 reply; 3+ messages in thread
From: Oguz Yilmaz @ 2010-04-14  8:30 UTC (permalink / raw)
  To: netfilter

OS is CentOS 5.4
Kernel is 2.6.18-164

Sometimes my firewall blocks the internet. When I inspect I have seen:
- nat PREROUTING counters increase
- filter FORWARD counters do not increase
- nat POSTROUTING counters do not increase

According to the diagram of Engelhardt,
http://jengelh.medozas.de/images/nf-packet-flow.png, the problem
should be in Bridging Decision point or acc.to former diagrams in
Routing Decision point.

I have tried to flush routing cache by "ip ro fl ca".

Problem is recovered only after /etc/init.d/iptables stop / start

I need further cues for deepen the problem, or exact reasons for
updating/recompling to newer kernel/netfilter.

Best Regards,

Oguz.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Packets stops traversing after nat PREROUTING
  2010-04-14  8:30 Packets stops traversing after nat PREROUTING Oguz Yilmaz
@ 2010-04-14  9:59 ` Jan Engelhardt
  2010-04-14 20:09   ` Oguz Yilmaz
  0 siblings, 1 reply; 3+ messages in thread
From: Jan Engelhardt @ 2010-04-14  9:59 UTC (permalink / raw)
  To: Oguz Yilmaz; +Cc: netfilter

On Wednesday 2010-04-14 10:30, Oguz Yilmaz wrote:

>OS is CentOS 5.4
>Kernel is 2.6.18-164
>
>Sometimes my firewall blocks the internet. When I inspect I have seen:
>- nat PREROUTING counters increase
>- filter FORWARD counters do not increase
>- nat POSTROUTING counters do not increase
>
>According to the diagram of Engelhardt,
>http://jengelh.medozas.de/images/nf-packet-flow.png, the problem
>should be in Bridging Decision point or acc.to former diagrams in
>Routing Decision point.
>
>I have tried to flush routing cache by "ip ro fl ca".
>
>Problem is recovered only after /etc/init.d/iptables stop / start
>
>I need further cues for deepen the problem, or exact reasons for
>updating/recompling to newer kernel/netfilter.

We need further cues like the ruleset.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Packets stops traversing after nat PREROUTING
  2010-04-14  9:59 ` Jan Engelhardt
@ 2010-04-14 20:09   ` Oguz Yilmaz
  0 siblings, 0 replies; 3+ messages in thread
From: Oguz Yilmaz @ 2010-04-14 20:09 UTC (permalink / raw)
  To: netfilter

Fortunately/unfortunately it was just because of ip_forward being 0. Thanks.


On Wed, Apr 14, 2010 at 12:59 PM, Jan Engelhardt <jengelh@medozas.de> wrote:
> On Wednesday 2010-04-14 10:30, Oguz Yilmaz wrote:
>
>>OS is CentOS 5.4
>>Kernel is 2.6.18-164
>>
>>Sometimes my firewall blocks the internet. When I inspect I have seen:
>>- nat PREROUTING counters increase
>>- filter FORWARD counters do not increase
>>- nat POSTROUTING counters do not increase
>>
>>According to the diagram of Engelhardt,
>>http://jengelh.medozas.de/images/nf-packet-flow.png, the problem
>>should be in Bridging Decision point or acc.to former diagrams in
>>Routing Decision point.
>>
>>I have tried to flush routing cache by "ip ro fl ca".
>>
>>Problem is recovered only after /etc/init.d/iptables stop / start
>>
>>I need further cues for deepen the problem, or exact reasons for
>>updating/recompling to newer kernel/netfilter.
>
> We need further cues like the ruleset.
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-04-14 20:09 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-04-14  8:30 Packets stops traversing after nat PREROUTING Oguz Yilmaz
2010-04-14  9:59 ` Jan Engelhardt
2010-04-14 20:09   ` Oguz Yilmaz

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