I AM USING Fedora Core 6
i have ppp0 connection to internet
and eth0 to lan

i flushed all the rules. All the policy are accepted

i used the command
#iptables -t nat -A POSTROUTING -o ppp0 -j MASQURADE

IP forwarding in my system is enabled
#vi /etc/sysctl.conf
net.ipv4.ip_forward = 1
and

/proc/sys/net/ipv4/ip_forward has value 1

i have win xp as a client
i have used the gateway as the ip defined on eth0 of the LINUX firewall box
all the ip are in the 192.168.0.0 network except the ip at ppp0(LINUX firewall box)
still my client box cant access the internet.
please help me

What DNS servers are the LAN clients configured to use? Can they ping them?

Moved: This thread is more suitable in Linux - Networking and has been moved accordingly to help your thread/question get the exposure it deserves.