Debian Configuration :: Internet With Isc-dhcp-serve

I need to shear internet i use isc-dhcp-serve and it work but internet doesn't work i have triad so many commends but still networking ... My setting is eth0 - wan eth1 -local

iface eth1 inet static
address 192.168.42.6
netmask 255.255.255.0

dhcp

authoritative;

subnet 192.168.42.0 netmask 255.255.255.0 {
range 192.168.42.10 192.168.42.50;
option broadcast-address 192.168.42.255;
option routers 192.168.42.1;
default-lease-time 600;
max-lease-time 7200;
option domain-name "local";
option domain-name-servers 8.8.8.8, 8.8.4.4;
}