PPP over Ethernet, or PPPoE, has traditionally been used as a method of authentication onto the line provider's network where a single IP address is assigned dynamically each time a new connection is established. Under some circumstances, as determined by the ISP, a block of addresses can be statically defined to the WAN interface of the router, with Network Address Translation being enabled for using private IP addressing on the LAN.

However, you can use these public addresses on the LAN interface of the Netopia router and disable NAT. With this type of account, this setup would be used in the place of traditional bridging. Instead of acting as a modem, the gateway continues to act in router mode. You would typically want to have a firewall device of some type behind the Netopia to provide your ultimate network security. This document outlines the configuration for this type of network scenario.

Please Note: If the ISP has assigned a single fixed (or dynamic) IP address to the WAN interface, and is routing a separate subnet block to the LAN interface of the router, this document is NOT applicable to your setup.

Please Note: If your router is currently running Netopia Enterprise Firmware version 8.0.10 and later, this technote is not applicable to you.

Related documents: CQG_015 Disabling Network Address Translation

Firmware Reference

• v7.2 and later -- Netopia 3300 Series
• v6.3 and later -- Netopia 3500 Series

Before You Start

Browse into the Netopia's web interface at http://192.168.1.254 (if using the default IP setting). If your network has a different IP addressing scheme, modify this accordingly.

Login with the admin user name and password. Admin login is required to save changes. If you are unsure of this, contact your network administrator.

Once logged in, click on the Expert Mode link in the left-hand side menu (if that link is visible). In the Expert Mode Confirmation screen click on Ok to continue. This menu bar will be visible at the top of your screen if you are in Expert Mode.

Remember to click the button to save any entries. Hitting the back button without clicking will undo any changes.

Once you have completed your configuration, click on the symbol in your upper right hand corner to validate the changes. Then click on Save and Restart.

 

The Netopia Web GUI Home Page in Expert Mode (Firmware v6.3 and later)

Configuration

1. In the upper menu bar, click on Configure.
2. Click on WAN.   Please Note: If your router was provided to you by the ISP, it probably has the correct values preconfigured for the ATM Circuit Encapsulation. If you see PPP over Ethernet VCC1 in the WAN IP Interfaces box, you can go directly to step #5.
3. Within Other WAN Options click on ATM.

   

   1. From the drop-down menu set the Encapsulation type to PPP over Ethernet.
   2. Set the VPI/VCI settings as specified by the ISP.
   3. Click Submit once you've made the appropriate changes .
4. Click on WAN to bring you back to the interface screen.
5. Under WAN IP Interfaces click on the PPP over Ethernet VCC1 link.
   
   
   1. Verify that Enable Interface is checked.
   2. Uncheck (disable) the Address Mapping (NAT), to use your routable Public IP addresses on your LAN.
   3. Set Restrictions to None.
   4. Enter the ISP Username and ISP Password. These have been given to you by your ISP.
   5. Connection Type is Always-On.
   6. Click on Submit.
6. Again click on WAN to bring you back to the WAN configuration screen.
7. Under IP Gateway:
   
   
   1. Make sure Enable Gateway Option is checked (on).
   2. Set Interface Type to PPP (vcc1).
   3. Click Submit.
8. Click on Configure in the upper menu bar.
9. Click on the LAN link.
10. Be sure Enable Interface is checked.
    1. Insert the appropriate LAN IP information.
    2. With NAT disabled, insert the public IP address that was assigned to the WAN of the router. This address in turn will become the default gateway for the workstations (or a firewall) on the LAN that are using public IP addresses.
    3. Enter the correct IP Netmask, typically 255.255.255.248.
    4. Leave Restrictions set to None.
    5. Click on Submit.
11. In the Other LAN Options box, click on DHCP Server.
    1. Set Server Mode to Off. PLEASE NOTE: If the Server function is on and the addresses are left at the factory default settings, your configuration changes will not be validated.
    2. Click on Submit.
12. Click on Configure in the upper menu bar.
13. Once you have input all appropriate information, click on the symbol in your upper right hand corner to validate the changes.
14. Click on Save and Restart.
15. At this point the router will reboot and when it comes back up it will be ready to connect.

Conclusion

This document has detailed the basic configuration parameters of the Netopia 3300 / 3500 Series ADSL Internet Gateway using PPPoE and a routed subnet.