Netopia R2121 User Reference Manual page 249

Remote IP Address:
Remote IP Mask:
Address Translation Enabled:
Filter Set...
Remove Filter Set
Receive RIP:
Enter the remote IP network's IP address (form xxx.xxx.xxx.xxx decimal).
Configure IP requirements for a remote network connection here.
Toggling Address Translation Enabled to Yes enables the Netopia R2121 to send out an all-zeros IPCP address
that requests an IP to be assigned to the Netopia R2121'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 R2121 is dialing is not always
known.
As mentioned earlier in this appendix, NAT works well for IP sessions originated on the Netopia R2121's LAN
interface destined for the Internet without any additional configuration. For incoming IP connections from the
Internet to a host on the Netopia R2121'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 R2121's LAN interface. An
example of this screen is as follows:
IP Profile Parameters
127.0.0.2
255.255.255.0
Yes
No
Understanding Netopia NAT Behavior D-7