sharing internet with iptables

From: Cothbw (Nomail_at_hotmail.com)
Date: 07/26/04 

Date: Mon, 26 Jul 2004 19:02:27 +0200

I've got a problem with iptables => sharing internet (can't connect to the
internet with my client)

I use mandrake 9.2 firewall guarddog and have a asdl-ppp0 connection.

To use the gateway of my server I got the advise to set up the server
like this:

1. first disable firewall
2. # echo 1 > /proc/sys/net/ipv4/ip_forward
3. # iptables -t nat -A POSTROUTING -o ppp0 -j MASQURADE

After that:
4. # iptables -t nat -L

no message

It should be something like:
------------------------------
Chain PREROUTING (policy ACCEPT)
target prot opt source destination

Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
MASQUERADE all -- anywhere anywhere

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
--------------------------------------------------

I hope someone can help me solve this problem (firewall related?), in a
dutch newsgroup I got some suggestions but they all failed.

Regards Cothbw

More info:

- Ifconfig:

eth0 Link encap:Ethernet HWaddr 00:04:23:1E:92:05
          inet addr:10.0.0.10 Bcast:10.0.0.255 Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:25478 errors:0 dropped:0 overruns:0 frame:0
          TX packets:12400 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:17533314 (16.7 Mb) TX bytes:1114002 (1.0 Mb)
          Interrupt:20 Base address:0x1000

eth1 Link encap:Ethernet HWaddr 00:10:B5:08:43:CC
          inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:28 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:7196 (7.0 Kb) TX bytes:240 (240.0 b)
          Interrupt:21 Base address:0x3f00

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          UP LOOPBACK RUNNING MTU:16436 Metric:1
          RX packets:182 errors:0 dropped:0 overruns:0 frame:0
          TX packets:182 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:9426 (9.2 Kb) TX bytes:9426 (9.2 Kb)

ppp0 Link encap:Point-to-Point Protocol
          inet addr:62.234.99.23 P-t-P:62.234.96.1 Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
          RX packets:945 errors:0 dropped:0 overruns:0 frame:0
          TX packets:995 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:72634 (70.9 Kb) TX bytes:50892 (49.6 Kb)

- route:

Destination Gateway Genmask Flags Metric Ref Use Iface
c3eea6001.cable * 255.255.255.255 UH 0 0 0 ppp0
10.0.0.0 * 255.255.255.0 U 0 0 0 eth0
192.168.1.0 * 255.255.255.0 U 0 0 0 eth1
127.0.0.0 * 255.0.0.0 U 0 0 0 lo
default c3eea6001.cable 0.0.0.0 UG 0 0 0 ppp0

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