Netopia R7200 Network Router User Manual


 
Understanding Netopia NAT Behavior C-7
Configuration
NAT is enabled by default with the SmartStart configuration utility. You can toggle Enable Address Translation to
No or Yes in the Connection Profile screen in System Configuration under the IP Profile Parameters section. NAT
is enabled on a per-profile basis, so it is possible to have any combination of NAT and non-NAT profiles. An
example of enabling NAT is as follows:
Toggling Address Translation Enabled to Yes enables the Netopia R7200 to send out an all-zeros IPCP address
that requests an IP to be assigned to the Netopia R7200’s WAN interface. Note that the remote IP address is
127.0.0.2, which should also be the default gateway under IP Setup in System Configuration. This is done for
profile matching purposes and because the IP address of the router the Netopia R7200 is dialing is not always
known.
As mentioned earlier in this appendix, NAT works well for IP sessions originated on the Netopia R7200’s LAN
interface destined for the Internet without any additional configuration. For incoming IP connections from the
Internet to a host on the Netopia R7200’s LAN interface, exported services need to be used.
Exported services are configured under IP Setup in System Configuration. This is where a particular type of TCP
or UDP service originating from the Internet is redirected to a host on the Netopia R7200’s LAN interface. An
example of this screen follows:
IP Profile Parameters
Remote IP Address: 127.0.0.2
Remote IP Mask: 255.255.255.0
Address Translation Enabled: Yes
Filter Set...
Remove Filter Set
Receive RIP: No
Enter the remote IP network's IP address (form xxx.xxx.xxx.xxx decimal).
Configure IP requirements for a remote network connection here.