DA-660-8/16-LX User’s Manual
Managing Communications
4-9
NOTE: In Example 8, remember to issue the command
#modprobe ipt_mac
first to load module
ipt_mac
.
NAT
NAT (Network Address Translation) protocol translates IP addresses used on one network to
different IP addresses used on another network. One network is designated the inside network and
the other is the outside network. Typically, the DA-660 connects several devices on a network and
maps local inside network addresses to one or more global outside IP addresses, and un-maps the
global IP addresses on incoming packets back into local IP addresses.
NOTE
Click on the following link for more information about iptables and NAT:
The IP address of LAN1 is changed to 192.168.3.127 (you will need to load the module
ipt_MASQUERADE):
Embedded Computer
PC1 (Linux or Windows)
IP/Netmask:
Gateway:
192.168.3.100/24
192.168.3.127
PC2 (Linux or Windows)
IP/Netmask:
Gateway:
192.168.4.100/24
192.168.4.127
LAN1
LAN2
LAN1: 192.168.3.127/24
LAN2: 192.168.4.127/24
NAT Area / Private IP
1.
echo “1” > /proc/sys/net/ipv4/ip_forward
2.
modprobe ip_tables
3.
modprobe ip_conntrack
4.
modprobe iptable_nat
5.
modprobe ipt_MASQUERADE
6.
iptables -t nat -A POSTROUTING -o ixp0 -j MASQUERADE
