hi
I need some help to configure my local network in order to share
internet connection between a linux machine (PC1) and a winXP laptop.
I don't understand anything to networks, and I've been trying for days,
bu no way... Please help !

My linux box (PC1) : Debian Sid, ker2.4.22, connected to the internet.
It works fine (web browsing, mail, etc...)

My laptop (PC2) : winXP pro, connected to PC1 by a wifi network. This
LAN seems to be working : I can ping PC1 from PC2 (and PC1 > PC2 too), I
can ping the DNS of my provider from the laptop too. But I cannot use
the web (IExplorer won't find anything).

I don't know if the problem comes from the winXP network configuration
or from the Debian configuration of my PC1 box.
I've tried to use iptables for the ip-forwarding, but I don't understand
very well how it works.

Can you help me ?

Here is my configuration on PC1 :
------------------------------------------------------------

#/etc/network/interfaces
auto lo
iface lo inet loopback
#automatic starting/stopping "iptables" rules
pre-up /etc/network/if-pre-up.d/iptables-start.sh
post-down /etc/network/if-post-down.d/iptables-stop.sh

# ethernet card, connected to the internet
auto eth0
iface eth0 inet dhcp

# usb wlan adapter netgear MA101(B)
auto eth1
iface eth1 inet static
address 192.168.0.1
network 192.168.0.0
netmask 255.255.255.0
broadcast 192.168.0.255
# activation of IP forwarding IP
up echo "1" > /proc/sys/net/ipv4/ip_forward
------------------------------------------------------------------

#****** /etc/network/if-pre-up.d/iptables-start.sh
#!/bin/sh
# starting "iptables" rules

iptables -F
iptables -t nat -F

iptables -P INPUT DROP

iptables -P FORWARD ACCEPT

iptables -P OUTPUT ACCEPT

iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

iptables -A INPUT -p tcp --dport 80 -j ACCEPT

iptables -A INPUT -p icmp -j ACCEPT

iptables -A INPUT -p igmp -j ACCEPT

iptables -A INPUT -i lo -j ACCEPT

iptables -A INPUT -j REJECT

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to-destination
192.168.0.2:80
-------------------------------------------------------------------

this is what I get from the ipconfig -a command :

eth0 Lien encap:Ethernet HWaddr 00:20:18:B8:948
inet adr:82.66.118.57 Bcast:82.66.118.255 Masque:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:499 errors:0 dropped:0 overruns:0 frame:0
TX packets:317 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:100
RX bytes:380220 (371.3 KiB) TX bytes:24224 (23.6 KiB)
Interruption:10 Adresse de base:0xb800

eth1 Lien encap:Ethernet HWaddr 00:09:5B:4B:2D:B0
inet adr:192.168.0.1 Bcast:192.168.0.255 Masque:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:162 errors:0 dropped:0 overruns:0 frame:0
TX packets:87 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:100
RX bytes:14922 (14.5 KiB) TX bytes:7881 (7.6 KiB)

lo Lien encap:Boucle locale
inet adr:127.0.0.1 Masque:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:807 errors:0 dropped:0 overruns:0 frame:0
TX packets:807 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:0
RX bytes:48398 (47.2 KiB) TX bytes:48398 (47.2 KiB)

--------------------------------------------------------------

here is what I get from the route -n command:

Table de routage IP du noyau
Destination Passerelle Genmask Indic Metric Ref Use Iface
82.66.118.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
0.0.0.0 82.66.118.254 0.0.0.0 UG 0 0 0 eth0

-----------------------------------------------------------------

Here is my winXP network configuration :

Utiliser l'adresse IP suivante:
adresse IP: 192.168.0.2
masque de sous reseau: 255.255.255.0
passerelle par defaut: 192.168.0.1

Utiliser l'adresse de serveur DNS suivante:
serveur DNS prefere: 212.27.32.176
serveur DNS auxiliaire: 212.27.32.177

sorry, it is in french
I guess 'masque de sous reseau' stands for 'submask'
'passerelle par défaut' stands for 'default gateway'
'serveur DNS prefere' stands for 'primary DNS'
'serveur DNS auxiliaire' stands for 'secondary DNS'

I apologize for my bad english