Messages in this thread | | | Date | Wed, 17 Jan 2001 19:01:26 +0100 | From | Andi Kleen <> | Subject | Re: IP defrag (was RE: ipchains blocking port 65535) |
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On Wed, Jan 17, 2001 at 05:44:30PM -0000, Tony Gale wrote: > > On 17-Jan-2001 Andi Kleen wrote: > > > > Connection tracking always defrags as needed. > > masquerading/NAT/iptables > > with connection tracking uses that. > > > > This means that if any of these are enabled and your machine acts > > as a > > router lots of CPU could get burned in defragmentation, and packets > > will not forwarded until all fragments arrived. > > Hmm... ok, what if I'm on a single nic system using ipchains on the > input and want to always defrag before they hit the ipchains > filter, what settings would I need? No masq., no NAT. (bearing in > mind that ipchains differentiates between SYN+frag and noSYN+frag.
You probably need to just load ip_conntrack_standalone and make sure it runs. It has a higher priority than ipchains in the prerouting chain and should just defragment things.
Better would it be to just write a small netfilter module with a higher priority than ipchains that always defrags.
Actually I thought I've once seen such a beast, but it doesn't seem to be included in the main kernel now that I look for it. It's all only a few lines of code anyways.
-Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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