Firewall Sending Resets(was Troubleshooting Netfilter Firewall (performance issues))

Jozsef Kadlecsik kadlec at
Sat Nov 5 17:25:23 CET 2005

On Fri, 4 Nov 2005, Harrison, James wrote:

> > netfilter sends RST if it was configured to do so by using the REJECT
> > target.
> >
> > No vanilla netfilter sends RST to client and server, in any setup.
> I understand, but the file transfer is initiated, begins, and can and
> will run for a period of time, then out of the blue it fires the RST.

Are you sure the firewall creates the RST segments?

> Why?

Dunno. You should capture the full traffic by tcpdump so that one could
analyze it. Without such a proof nothing much can be said. Also, one would
require the list of netfilter patches (from patch-o-matic or others)
applied on top of kernel 2.4.31 in devil-linux.

Best regards,
E-mail  : kadlec at, kadlec at
PGP key :
Address : KFKI Research Institute for Particle and Nuclear Physics
          H-1525 Budapest 114, POB. 49, Hungary

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