Subject: Re: [PATCH 1/1] netfilter: Add possibility to turn off netfilters defrag per netns

From: Hans Schillstrom <[email-masked]>
Date: Wed, 4 Jan 2012 09:49:53 +0100

Hello Jozsef

On Wednesday 04 January 2012 09:28:05 Jozsef Kadlecsik wrote:
> Hi Hans,
> 
> On Wed, 4 Jan 2012, Hans Schillstrom wrote:
> 
> > In some cases it not desirable to have auto defrag.
> > Ex. in a cluster where packets can arrive on different blades.
> > In that case it is possible to use containers (LXC) and send
> > all fragments to one place where defrag is enabled.
> > 
> > This patch makes it possible to turn off the defrag per network name space,
> > by setting net.netfilter.nf_conntrack_nodefrag to 1.
> > Both IPv4 and IPv6 is effected by this sysctl.
> > Default is 0 which is defrag.
> 
> Conntrack assumes that the packets are defragmented and will drop any 
> unfragmented one. So your patch results packet drops.

Hmmm, more work...
> 
> Also, if you want to disable defragmentation then why don't you simply 
> "mark" the packets with the NOTRACK target?

I don't think that will work since NF_IP_PRI_CONNTRACK_DEFRAG is -400

> Best regards,
> Jozsef

-- 
Regards
Hans Schillstrom <[email-masked]>