On Monday 10 June 2002 12:17 pm, [EMAIL PROTECTED] wrote:

> when I use :
>
> iptables -I POSTROUTING  -t nat -p icmp --icmp-type \
> fragmentation-needed -j LOG --log-prefix "icmp SNAT POST "
>
> iptables -I PREROUTING -t mangle  -p icmp --icmp-type \
> fragmentation-needed -j LOG --log-prefix "icmp SNAT PRE "
>
> I can see them in PREROUTING but not in POSTROUTING...

Do you have a suitable FORWARDing rule to transfer these packets across the 
box ?

When you log them in the PREROUTING chain, they don't have the destination 
address of the netfilter box itself, do they ?   (ie they're stopping on the 
local box and not trying to route any further...)

Antony.

> On Mon, 10 Jun 2002, Antony Stone wrote:
> > On Monday 10 June 2002 11:36 am, [EMAIL PROTECTED] wrote:
> > > > > I would like to SNAT icmp fragmentation-needed messages that have
> > > > > source address from private network range (RFC1918), I have tried
> > > > > something like:
> > > > >
> > > > > iptables -t nat  -I POSTROUTING -j SNAT --to real_address -p icmp 
> > > > > \ --icmp-type fragmentation-needed -s 192.168.0.0/16
> > > > >
> > > > > but it does not work.
> > > >
> > > > What happens if you put a logging rule immediately before this one:
> > > >
> > > > iptables -I POSTROUTING -t nat -s 192.168.0.0/16 -p icmp --icmp-type
> > > > fragmentation-needed -j LOG --log-prefix "icmp SNAT"
> > > >
> > > > Do you get any packets logged ?
> > >
> > > Nothing gets logged......
> >
> > In that case you have no packets of the type you are trying to match.....
> >
> > ...which is why they don't get SNATted.
> >
> >
> >
> > Antony.

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