Server List (Port Forwarding)
With NAT enabled, the IP addresses of nodes on your LAN are private since they are hidden from the Internet.
let you pass specific types of network traffic through
the Netopia router's NAT interfaces. Once configured, selected types of
network traffic, such as FTP requests or HTTP (Web) connections, will
be forwarded to a specific host or server behind the Netopia router.
From the LAN (Local Area
Network), you will also be able to access the servers that are
responding to requests from the internet, but only using the internal
private IP address. Access via the public IP address is not supported
from a local ethernet connection.
If your ISP is routing you multiple public IP addresses, you can also
configure the router to forward all ports in one public IP to a
designated private IP address on your LAN via Easy PAT List
entries. For those instructions, see Quick Guide NQG_024: IP Mapping (Address Forwarding).
If your router is currently running Netopia Residential Firmware
with a web "GUI" configuration menu, this technote is not applicable to
you. Most 3300 Series Netopia Gateways can be upgraded to Enterprise
level firmware. Click Here!
to purchase the upgrade key.
Related documents: NQG_039 NAT and the Basic Firewall
- v8.2 R1 (and up) - 3300 Enterprise Series
- v5.3.7 (and up) - 4000 Series
- v4.8.2 (and up) - R-Series
Before You Start
Telnet into the Netopia router's Main Menu at 192.168.1.1 (if using the default IP setting).
If your network has a different IP addressing scheme, modify this accordingly. Click Here! for instructions on using telnet and Hyperterminal (serial connection).
Login with the user name and password. The Superuser login is required to save changes.
If you are unsure of this, contact your network administrator.
Don't forget to press the Enter key to save any entries. Hitting the back space, delete or tab without first hitting enter will undo any changes.
The Esc key will take you back towards the main menu screen.
Once you have completed your configuration, you should reboot the Netopia to save and apply your changes.
The Netopia Main Menu Interface
Server List Configuration
- From the Main Menu of router console screens, go to Quick Menus, and select Network Address Translation.
- Select Show/Change Server List.
- Select Easy-Servers.
- From the Show/Change NAT Server List screen, select Add Server.
- Select Service and the service and port you want to allow. If your service and port are not available in the pull-down menu, select Other. Selecting Other will allow you to enter a specific service port or a range of ports since fields are provided for both a First Port Number and a Last Port Number. To allow a specific service port, the First Port Number and Last Port Number should be the same. Select Okay.
- Next, enter the Server Private IP Address, or the private IP address of the host/server you are forwarding the service to, and the Public IP Address you want to associate with the same host/server. This value can be left set to 0.0.0.0 if you are using the WAN IP as the Public IP address.
Note: If your ISP is routing you multiple static IP
addresses, other then the one used for Internet access, you may create
more than one server for specific service as long as all servers have a
different Public IP Address specified. For example, with two web
servers on your LAN you would need to create two Server List entries for
TCP 80 (www-http). Since each specific port (service) can only be
mapped once using any given Public IP Address, a distinct public
address must be used for each TCP 80 server list entry. It is not
necessary for you to specify more than one Local WAN IP Address or Public IP Address
in your router's configuration. As long as you are connecting to your
ISP via a public IP address used for NAT, they are responsible for
routing all other IP addresses via that connection.
You have now configured your router for TCP/UDP port forwarding. If
you have a switched connection (ISDN or Analog), you will need to either
reconnect your Internet connection, or restart your router for the Nat Server List changes to take effect. If you wish to filter traffic for your static IP mappings, please see the following Netopia Technote:
NQG_039: NAT and the Basic Firewall