From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Stefan Mueller" <smueller@s-mueller.ch>
Subject: performance troubles
Date: Sun, 3 Nov 2002 14:01:41 +0200
Sender: netfilter-admin@lists.netfilter.org
Message-ID: <20021103120141.M65262@s-mueller.ch>
Mime-Version: 1.0
Return-path: <netfilter-admin@lists.netfilter.org>
Errors-To: netfilter-admin@lists.netfilter.org
List-Help: <mailto:netfilter-request@lists.netfilter.org?subject=help>
List-Post: <mailto:netfilter@lists.netfilter.org>
List-Subscribe: <https://lists.netfilter.org/mailman/listinfo/netfilter>,
	<mailto:netfilter-request@lists.netfilter.org?subject=subscribe>
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: <https://lists.netfilter.org/pipermail/netfilter/>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: netfilter@lists.netfilter.org

Hello
i have a performance problem with my new SNAT (masquerade).
i have a cable modem with 512kbit/s. downloading a 1MB file takes 30s without 
NAT. downloading the same file from a pc behind NAT takes 500s! (2.5kbit/s)

OK, some information:
the NAT Router:
-AMD 1800+
-512MB DDR-Ram
-10MBit Card to the Cablemodem (the cabelmodem has a 10Mbit connector)
-100MBit to the Intranet
-Redhat 8.0 (2.4.18-14)
-iptables v1.2.6a
-load average 0.00 0.00 0.00
-no entrys in /var/log/messages
-iptables -L -> nothing,policy ACCEPT in INPUT OUTPUT FORWARD
-using iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
-interfaces:
 eth0 217.162.74.155 mask 255.255.254.0 (dhcp)
 eth1 10.22.0.1      mask 255.255.0.0
-routing table:
 217.162.74.0 *              255.255.254.0 U  0 0 0 eth0
 10.22.0.0    *              255.255.0.0   U  0 0 0 eth1
 127.0.0.0    *              255.0.0.0     U  0 0 0 lo
 default      (isp's router) 0.0.0.0       UG 0 0 0 eth0

the Client
-AMD 1800+
-512MB DDR-Ram
-100MBit to the Intranet
-Redhat 8.0 (2.4.18-14)
-load average 0.00 0.00 0.00
-iptables v1.2.6a
-no entrys in /var/log/messages
-iptables entrys
-interfaces:
 eth0 10.22.32.1 mask 255.255.0.0
-routing table:
 10.22.0.0 *         255.255.0.0 U  0 0 0 eth0
 127.0.0.0 *         255.0.0.0   U  0 0 0 lo
 default   10.22.0.1 0.0.0.0     UG 0 0 0 eth0

transmission between server and client has normal 100Mbit speed.
ping from the client to the internet is normal at ~100ms

what did i wrong? i know that NAT can't be as fast as a direct connection but 
this is terrible slow...
--
Open WebMail Project (http://openwebmail.org)