Re: ip6tables breaks dnssec?

[Leo Baltus <Leo.Baltus@omroep.nl>]

Op 27/04/2011 om 12:43:19 +0200, schreef Ulrich Weber:
> Each fragmented IPv6 packets will traverse netfilter separately,
> in contrast to IPv4, where its only one refragmented packet.
> 

I seem to have missed that.

> "ip6tables -A INPUT -j ACCEPT -p udp --dport 53" will only match the
> first fragment, where the UDP header can be found. To match the
> additional fragments, you have to insert these rules:
> 
> ip6tables -I INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
> ip6tables -I OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
> 

Thanks. That was it.

> On 04/27/2011 12:08 PM, Jan Engelhardt wrote:
> > On Wednesday 2011-04-27 10:57, Leo Baltus wrote:
> > 
> >> Hi,
> >>
> >> When doing recusive dns queries to dnssec-enbled servers it looks like
> >> ip6tables does not assemble udp packets before filtering takes place.
> >> This results in fragments being dropped.
> > 
> > You need to have nf_defrag_ipv6 loaded for automatic defragmentation. 
> > There are only a few components that depend on it - nf_conntrack and 
> > TPROXY, so it may not be autoloaded if you do not use either.
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