Hi all..I am a Newbie...

I have a box with two eth cards..I want to use my box as gateway for my internal LAN.

the default kernel routing table in the box is pointin to my ISP gateway. I can reach it from the box, but cannot from behind the box ie LAN. I want to be able to reach my external hosts from my LAN.

Any Ideas will be greatly appreciated

internal LAN IP 192.168.1.0/24 & box with 192.168.1.1 for LAN

Box with 217.199.148.13/24 for eth conneting to ISP

rgds

You need two things. An interfaces file with the correct ip and gatway info and a firewall script which enables masquerading.

Your interfaces config file might look something like this:

auto eth0
iface eth0 inet static
address 192.168.1.1
netmask 255.255.255.0

auto eth1
iface eth1 inet static
address 217.199.148.13
netmask 255.255.255.240
gateway 217.199.148.X

X, in this case, will be what your ISP assigns for your gateway.


Something like this for your firewall will be a start:

# flush the existing firewall rules
iptables -t nat -F
iptables -F
iptables -X

# MASQUERADE the connection (-j MASQUERADE).
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

# Turn on IP forwarding
echo 1 > /proc/sys/net/ipv4/ip_forward