hi every one
the problem : iam using mandrake 10.1 as a server and the win xp as a client i'm trying to share the two computers but i get a problem with the two sides their is no ping to each ather and as result i can't share files and internet .

describing : the win xp network is using this data
1. ip add: 192.168.0.3
2. sub mask : 255.255.255.0
3. default getway: 192.168.0.1
4. prefferd dns server : 192.115.106.35
5. alternate dns : 62.219.186.7

linux mandrake 10.1
using usb as internet connection as eth1

lan ip address 192.168.0.1
the ifconfig result is :

eth0 Link encap:Ethernet HWaddr 00:50:BF:7D:07:02
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::250:bfff:fe7d:702/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:20152 errors:63 dropped:0 overruns:0 frame:0
TX packets:41588 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:16267222 (15.5 Mb) TX bytes:11658758 (11.1 Mb)
Interrupt:9 Base address:0xec00

eth1 Link encap:Ethernet HWaddr 00:E0:6F:7D:B6:C3
inet addr:62.219.56.69 Bcast:255.255.255.255 Mask:255.255.255.0
inet6 addr: fe80::2e0:6fff:fe7d:b6c3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:527401 errors:0 dropped:0 overruns:0 frame:0
TX packets:494295 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:247243093 (235.7 Mb) TX bytes:266118586 (253.7 Mb)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:25184 errors:0 dropped:0 overruns:0 frame:0
TX packets:25184 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2592135 (2.4 Mb) TX bytes:2592135 (2.4 Mb)
linux host name is server 192.168.0.1
windows xp hostname s1 192.168.0.3
the getway is 192.168.0.3
when i tried to ping 192.168.0.3 the result is :

pING 192.168.0.3 (192.168.0.3) 56(84) bytes of data.
From 192.168.0.1 icmp_seq=2 Destination Host Unreachable
From 192.168.0.1 icmp_seq=3 Destination Host Unreachable

when i tried to ping 192.168.0.1 the result is :
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=0.072 ms
working
also on the ather side win xp when i tried to ping 192.168.0.1 the result is :
reqest time out their a send and their isn't a recevied
but by pinging 192.168.0.3 it's ok
so becuse of this i can't share the files and internet
ont he ather side i tried to write this command on the shell
echo 1>ip_forward
i used cat ip_forward the result is no namber but has to be 1 or eth1
also iused withe commnad line iptables -t nat -I POSTROUTING -o eth1 -j MASQUERADE
so as a result i can't use the inter net and the sharing files .

please try to help me

thanks for every one who can help