Moxa V2406-24I-T-XPE [37/81] Nat example

V2406/2422/2426 Linux User’s Manual Managing Communications

3-13

ATTENTION

In Example 8, remember to issue the command # modprobe ipt_mac first to load the module ipt_mac.

NAT (Network Address Translation)

The NAT (Network Address Translation) protocol translates IP addresses used on one network into IP

addresses used on a connecting network. One network is designated the inside network and the other is the

outside network. Typically, the V2406/2422/2426-LX 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.

ATTENTION

Click on the following link for more information about NAT:

http://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO.html

NAT Example

The IP address of all packets leaving LAN1 are changed to 192.168.3.127 (you will need to load the module

ipt_MASQUERADE):

Enabling NAT at Bootup

In most real world situations, you will want to use a simple shell script to enable NAT when the

V2406/2422/2426-LX boots up. The following script is an example.

#!/bin/bash

# If you put this shell script in the /home/nat.sh

# Remember to chmod 744 /home/nat.sh

# Edit the rc.local file to make this shell startup automatically.

# vi /etc/rc.local

# Add a line in the end of rc.local /home/nat.sh