| Written by: DJ | Date: 12/1/97 |
| Last Revised by: Stephanie Ryken | Date: 6/22/00 |
Applications that are incompatible with Network Address Translation (NAT).
Parameters:
Below is a list of hardware and firmware loads that this Technical Note is based upon:
| Hardware | Firmware/Version | Installed Options |
| Any Netopia R-Series Router | 4.3 or later | NAT Enabled |
| Any Netopia 400/600 Series Router | 3.1.3 or later | NAT Enabled |
To update your router firmware, go to our firmware update page.
Network Configuration:
This is the configuration of the hardware that is referenced in this Technical Note:
Background:
With NAT, the Netopia router gets a dynamic IP address from an ISP. Exported Services can be set up in the router to direct inbound traffic from the most commonly used applications (HTTP, FTP, Telnet, etc.) to a specific workstation on the LAN. These services are already setup for possible export in the router firmware.
Other services may be exported using user-definable ports as well. Some examples would be:
Some applications will not work in this situation, even though their ports have been exported.
For Example:
The Audio/Video features of Microsoft's Net Meeting are incompatible with NAT. The reason is that the ports that carry that information are dynamic and are not able to be processed by address translation. An outbound session will work, but the inbound session will not.
In IRC, the DCC functions cannot be initiated properly because the IP address is embedded in the data portion of the packet. This also cannot be processed by network address translation.
Some Internet Gaming software uses dynamic TCP and/or UDP ports and cannot function with NAT. Check with the program's manufacturer to obtain the ports used by your application.
Summary:
Getting a router account from your ISP with enough IP addresses for all of your machines will eliminate any problems related to NAT.
If you are using NAT and having a problem with a specific application, check with the manufacturer of your application to obtain the TCP and UDP ports used by the program. Once you have obtained that information, please see the following technote, applicable to your model of router and version of firmware, for more information on how to configure:
NQG_008: Setting up Exported Services on a Netopia 400/600 Series router running NAT
NQG_019: Setting up Exported Services on a Netopia R-Series router that is running NAT
If you have an R-Series router running firmware version 4.4 or above, please refer to the following technote:
NQG_025: Configuring a Server List on a Netopia R-Series router
