IPL ROUTER SET-UP
Page 60
Setup Guide 9023409-01
Ethernet ADSL Cellular Routeur Firewall
Advanced NAT
15.1
Overview
The advanced NAT function consists in modifying the source or destination IP addresses and port number
of the frames received by the ETIC router on its LAN or WAN interface.
It applies to all the frames received by the router on any of its two interfaces except to the IP packets
contained in a remote user connections.
One brings out
the DNAT function which consists in replacing the destination port and IP address.
the SNAT function which consists in replacing the source IP address.
Because the DNAT and SNAT functions modify the IP addresses of the IP packets processed by the RAS-3G
router, and because the firewall filters that frames, it is very important to understand in which order that
different functions are carried out.
Direction
WAN to LAN
LAN to WAN
DNAT
FIREWALL
SNAT
WAN
LAN
Router
LAN
SNAT
DNAT
WAN
FIREWALL
Router