Hi
I just got a new laptop and set up a small lan, my primary PC which is connected to the internet has two nic cards, one is conected to the DSL and the other one is connected to the LAN I just setup

My laptop ip is: 10.1.1.2 netmask 255.255.255.0
MY PC IP is: 10.1.1.1 netmask 255.255.255.0, it also has the ppp0 connected to the internet.
All the net filter modules are loaded into the kernel
ipt_MASQUERADE 4224 1
iptable_nat 25668 2 ipt_MASQUERADE
ipt_REJECT 7168 0
ipt_state 2176 0
ip_conntrack 45108 3 ipt_MASQUERADE,iptable_nat,ipt_state
iptable_filter 3200 1
ip_tables 18304 5 ipt_MASQUERADE,iptable_nat,ipt_REJECT,ipt_state,iptable_filter

When I want to give my laptop access to the internet this is what I do:

1) iptables -A POSTROUTING -t nat -o ppp0 -j MASQUERADE
2) echo 1 > /proc/sys/net/ipv4/ip_forward

My PC kernel is 2.6.9 and the latptop kernel is 2.6.10

When I try to ping any IP address from my laptop I do not receive any reply
I tried pinging my ISP DNS, yahoo, etc. But I don't reach anything..
Am I missing something?
Thanks

Try adding a rule to allow traffic on the forwarding chain:

iptables -I FORWARD -j ACCEPT

Note that this is a temporary rule that for testing purposes that will open up the entire LAN to outside traffic and should be removed afterwards. If that doesn't work, try posting your entire firewall script (or output of iptables -vnL and iptables -t nat -vnL). Also you haven't said whether the laptop can ping the internal LAN interface (10.10.1.1). I'm also assuming that you've connected the laptop to the linux box with a crossover-cable (not standard ethernet patch cable) or through a hub/switch?

Futhermore,
The gateway of the laptop should be the IP address of the PC i.e. 10.1.1.1. If you configured the laptop with a static IP address you will need to add the DNS info to the /etc/resolv.conf file just like the PCs.

Thank you!
I just figured out waht it was.... When I initially installed the fedora core 3, I enabled the firewall on the installation screen.

So i just used the setup command and I customized it, by allowing the traffic thru eth0, eth1 and ppp0
Thanks for your help
Regards