If your ISP has assigned you multiple static IP addresses you may want to have one or more of these IP's assigned directly to hosts or servers behind the Netopia with NAT enabled. If you want to place a public IP onto the local workstation, (i.e. not a 192.168.1.x address), then this Quick Guide will take you through this process step-by-step. How this is done will be determined by the type of routing (or bridging) handled from the ISP. The IP's can be routed to the Ethernet interface of the router, or be bridged to you on the WAN interface.
This configuration will transparently map your public IP addresses in a way that will allow you to configure workstations behind the router to hold these public IP addresses and make them publicly accessible, bypassing the NAT process on this secondary subnet.
Please Note: The IP addresses used in the following scenarios are examples only. Substitute the appropriate values of your network and internet addresses.
Methods covered are:
Example 1 : Routed subnet on the Ethernet Interface
Example 2 : Subnet bridged to the WAN Interface by ISP
Please Note: 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.
Firmware References:
- v8.2 R1 (and up) - 3300 Enterprise Series
- v5.3.7 (and up) - 4000 Series
- v4.8.2 (and up) - R-Series
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
| Local WAN IP Address: | 208.128.182.25 |
| Local WAN IP Mask: | 255.255.255.0 |
| Default IP Gateway: | 208.128.182.1 |
| Ethernet IP Address: | 192.168.1.1 |
| Ethernet IP Mask: | 255.255.255.0 |
| Ethernet Subnet Range (allocated by ISP): | 64.25.38.225-64.25.38.230 |
| Ethernet Subnet Mask: | 255.255.255.248 |
- Go to Quick Menus, and select IP Setup
- Select Define Additional Subnet
- For the #2 subnet, enter the first available IP Address from the subnet range that your ISP has allocated to you. In our example, this address would be: 64.25.38.225. The Subnet Mask will be 255.255.255.248.
- Once you have configured the router for an IP address on the second subnet, hit escape twice to return to the Quick Menus screen. Select Network Address Translation.
- Select Add Public Range.
- Enter the Range Name of your choice; for Type, select static.
- Enter the First Public Address and Last Public Address you want to map. If you want to map the entire subnet, start with the first usable address that you assigned to the router (in our example this would be 64.25.38.225), and end with the last usable address in your range (in our example this would be 64.25.38.230).
- Once both addresses are entered, select Add NAT Public Range.
- From the Network Address Translation screen, select Show/Change Map List.
- Select Easy-PAT List.
- From the Show/Change NAT Map List screen, select Add Map.
- Enter the same IP address that you entered for First Public Address in step 7 as the First Private Address, as well as the Last Public Address as the Last Private Address.
- Once both addresses are entered, select Use NAT Public Range.
- Select the static map you previously created in step 7. Select Add Map.
- From the Show/Change NAT Map List screen select Move Map.
- Select your pat map, configured by default, hit enter and use your arrow keys to move the map to the bottom of the list. Hit enter again to secure it's position and you will be returned to the previous menu screen.
Note: It is highly recommended that you use the default map list Easy-PAT List already created and enabled. If you wish to configure your own NAT Map List, you must include the default PAT (Port Address Translation) map included in the Easy-PAT List (Private Address Range 0.0.0.0 to 255.255.255.255 and Public Address Range 0.0.0.0 to --). You will also need to enable your own NAT Map List in your Internet connection profile.
Please Note: Because the Netopia router can not be used as a bridge, you must divide any subnet your ISP may bridge to you on the WAN interface. The block they assign you must follow IP subnetting rules. It must be a contiguous block of addresses with an associated subnet mask or this will not work. After breaking up the subnet, you will be able to use them as two separate IP subnets -one for the WAN interface, and the second for Transparent Mapping on the LAN interface.
Remember, the IP addresses used in this example are for illustration purposes only. Use only the addresses that have been assigned to you by your ISP and those that are correct for your local LAN settings.
| Local WAN IP Address: | 63.254.10.2 |
| Local WAN IP Mask: | 255.255.255.240 |
| Default IP Gateway: | 63.254.10.1 |
| Ethernet IP Address: | 192.168.1.1 |
| Ethernet IP Mask: | 255.255.255.0 |
| WAN Subnet Range (allocated by ISP): | 63.254.10.3-63.254.10.14 |
The first step in this scenario is to break down the subnet on the WAN side into two blocks. You can not use the same subnet on both WAN and LAN sides of the Netopia, thus you must divide them into two subnets.
Separate the WAN subnet into two segments:
For example, if the subnet range is: 63.254.10.1-63.254.10.14
You can break the IP addresses into two subnets : 63.254.10.1-63.254.10.6 and 63.254.10.9-63.254.10.14 each with a subnet mask of 255.255.255.248 (changed from the previous subnet of 255.255.255.240). Now, with your divided IP subnet ready, you can begin configuring the router.- Go to Quick Menus, and select IP Setup.
- Select Define Additional Subnet.
- For the #2 subnet, enter the first available IP Address from the subnet range that your ISP has allocated to you. In our example, this address would be: 63.254.10.9. The Subnet Mask will be 255.255.255.248.
- Once you have configured the router for an IP address on the second subnet, hit escape twice to return to the Quick Menus screen. Select Network Address Translation.
- Select Add Public Range.
- Enter the Range Name of your choice; For Type, select static.
- Enter the First Public Address and Last Public Address you want to map. If you want to map the entire subnet, start with the first usable address that you assigned to the router (in our example this would be 63.254.10.9), and end with the last usable address in your range (in our example this would be 64.25.38.14).
- Once both addresses are entered, select Add NAT Public Range.
- From the Network Address Translation screen, select Show/Change Map List.
- Select Easy-PAT List.
Note: It is highly recommended that you use the default map list Easy-PAT List already created and enabled. If you wish to configure your own NAT Map List, you must include the default PAT (Port Address Translation) map included in the Easy-PAT List (Private Address Range 0.0.0.0 to 255.255.255.255 and Public Address Range 0.0.0.0 to --). You will also need to enable your own NAT Map List in your Internet connection profile.
- From the Show/Change NAT Map List screen, select Add Map.
- Enter the same IP address that you entered for First Public Address in step 7 as the First Private Address, as well as the Last Private Address.
- Once both addresses are entered, select Use NAT Public Range.
- Select the static map you previously created in step 7. Select Add Map.
- From the Show/Change NAT Map List screen, select Move Map.
- Select your pat map, configured by default, hit enter and use your arrow keys to move the map to the bottom of the list. Hit enter again to secure it's position and you will be returned to the previous menu screen.
You've now configured your Netopia router to transparently map your public IP addresses in a way that will allow you to set up workstations on the LAN to hold these public IP addresses. These computers will now be publicly accessible, bypassing the NAT process on this secondary subnet.