Re: Problems removing rules

[SaVaGE <pc-secure@home.nl>]

Op donderdag 1 mei 2003 02:07, schreef Intercomax:
> I'm having a huge problem:
>
> I have those rules:
>
> Chain PREROUTING (policy ACCEPT)
> target     prot opt source               destination
> DNAT       tcp  --  anywhere             anywhere
>      tcp dpt:www
> to:192.168.0.1:80
>
> Chain POSTROUTING (policy ACCEPT)
> target     prot opt source               destination
> MASQUERADE  all  --  anywhere             anywhere
>
> Chain OUTPUT (policy ACCEPT)
> target     prot opt source               destination
>
> I inserted iptables -t nat -I PREROUTING -s
> xxx.xxx.xxx.xxx -j RETURN
>
> OK. The rules works fine.
>
> Then I removed the RETURN iptables -t nat -D
> PREROUTING -s
> xxx.xxx.xxx.xxx -j
> RETURN and... The IP still access some pages that
> accessed before!
>
> Why?
>
> I need to redirect all internal requests to a specific
> page and then,
> after a
> login, masquerade them to the Internet...
>
> That's it.
>
> Thanks in advance.
>
> Maurício S. Mudrik
>
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As far I can see by your rules , your running a Web-server on 192.168.0.1:80  
, not specific a rule to aply local acces to the internet.

But as i see the POSTROUTING chain , i miss something namely your output 
interface !!  like this ::;
Chain POSTROUTING (policy DROP)
num  pkts bytes target        prot       opt      in   out     source      
  *        *     * MASQUERADE  all  --  *         *    eth0    0.0.0.0/0            

destination
0.0.0.0/0

what about that login , i think Squid could do something like that , so you 
have to use a proxy for that.

Pascal