From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jim Laurino <nfcan.x.jimlaur@dfgh.net>
Subject: Re: configure firewall & NAT & cache with each other (nfcan:
	addressed to exclusive sender for this address)
Date: Sun, 30 Jan 2005 13:03:46 -0500
Message-ID: <20050130180346.GG10037@salty>
References: <20050130041539.25496.qmail@web51905.mail.yahoo.com>
Reply-To: nfcan.x.jimlaur@dfgh.net
Mime-Version: 1.0
Content-Transfer-Encoding: 8bit
Return-path: <netfilter-bounces@lists.netfilter.org>
Content-Disposition: inline
In-Reply-To: <20050130041539.25496.qmail@web51905.mail.yahoo.com> (from
	+nfcan+jimlaur+9c195b7875.yazdani1193#yahoo.com@spamgourmet.com
	on Sat, Jan 29, 2005 at 23:15:39 -0500)
List-Id: <netfilter.vger.kernel.org>
List-Unsubscribe: <https://lists.netfilter.org/mailman/listinfo/netfilter>,
	<mailto:netfilter-request@lists.netfilter.org?subject=unsubscribe>
List-Archive: </pipermail/netfilter>
List-Post: <mailto:netfilter@lists.netfilter.org>
List-Help: <mailto:netfilter-request@lists.netfilter.org?subject=help>
List-Subscribe: <https://lists.netfilter.org/mailman/listinfo/netfilter>,
	<mailto:netfilter-request@lists.netfilter.org?subject=subscribe>
Sender: netfilter-bounces@lists.netfilter.org
Errors-To: netfilter-bounces@lists.netfilter.org
Content-Type: text/plain; format="Flowed"; delsp="Yes"; charset="us-ascii"
To: netfilter@lists.netfilter.org

On 2005.01.29 23:15, Alireza Yazdani - yazdani1193@yahoo.com wrote:
> 
> Hello all,
> 
> I have 2 box for cache, bandwidth manager, firewall, NAT .
> 
> one box is cache server(squid) only. and another box is bandwidth manager,
> firewall, NAT server.
> 
> I haven't any rule on my squid box. the default gateway of my users is my
> firewall box. my firewall box has 2 ethernet(user side and internet side).
> 
> ip of firewall box is :
> 
> iptables_box_ILAN=172.16.5.5 (user side)(eth0)
> 
> iptables_box_WLAN=212.213.38.100 (internet side)(eth1)
> 
> ip of cache box is :
> 
> squid_box=172.16.5.6
> 
> the default gateway of cache box is firewall box
> 
> I use of this rule for NAT :
> 
> iptables -t nat -A POSTROUTING -s 172.16.5.0/24 -o eth1 -j SNAT --to
> 212.213.38.100
> 
> now I want redirect the request on port 80 to cache box :
> 
> local_network=172.16.5.0/24
> 
> iptables_box_ILAN=172.16.5.5
> 
> iptables_box_WLAN=212.213.38.100
> 
> iptables -t nat -A PREROUTING -i eth0 -s ! $squid_box -p tcp --dport 80 -j
> DNAT --to $squid_box:3128
> 
> iptables -t nat -A POSTROUTING -s $local_network -d $squid_box -o eth0 -j
> SNAT --to $iptables_box_ILAN

I think you do not need to do SNAT here for the local hosts.
The DNAT rule, above, should be enough.
This is not a rule to SNAT the squid box to the internet,
which you probably do want to do.

Recall that you do not say exactly what is not working,
so I can not be sure how to diagnose the problem.

One advice I can give is that the most powerful tool
for firewall trouble-shooting is
the built-in rule-match counters.

To review the counts, use something like:

	iptables -L -nvx >> file-for-review
or
	iptables -t nat -L -nvx >> file-for-review

The counts show you which rules are matching,
and allow you to trace the source of the problem.

> 
> iptables -A FORWARD -s $local_network -d $squid_box -i eth0 -o eth0 -p tcp
> --dport 3128 -j ACCEPT
> 
> when I don't use of NAT it is correct. and when I set all on one ethernet it
> is correct.
> 
> but when I have two ethernet and I NAT on firewall box it's not work  
> correct.
> 
> Please help me.
> 
> Thanks.

-- 
Jim Laurino
nfcan.x.jimlaur@dfgh.net
Please reply to the list.
Only mail from the listserver reaches this address.