Configuring IPoA Interfaces

Topics on this page: Viewing Your IPoA Interface Setup | Adding IPoA Interfaces

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This topic describes how to configure an IPoA (Internet Protocol over ATM) interface on the ADSL/Ethernet router.

An IPoA interface can be used to exchange IP packets over the ATM network, without using an underlying Ethernet over ATM (EOA) connection. Typically, this type of interface is used only in product development environments, to eliminate unneeded variables when testing IP layer processing.

Viewing Your IPoA Interface Setup 

If the IPoA page is not already displaying, click the WAN tab, and then click IPoA in the task bar.

The IPoA table contains a row for each EOA interface currently defined on the device. The table may initially contain no entries. The fields on this page are described as follows:

  • Interface: The name the software uses to identify the IPoA interface
  • Interface Security Type: The type of firewall protections that are in effect on the interface (public, private, or DMZ):
    • A public interface connects to the Internet (IPoA interfaces are typically public). Packets received on a public interface are subject to the most restrictive set of firewall protections defined in the software.
    • A private interface connects to your LAN, such as the Ethernet interface. Packets received on a private interface are subject to a less restrictive set of protections, because they originate within the network.
    • The term DMZ (de-militarized zone), in Internet networking terms, refers to computers that are available for both public and in-network accesses (such as a company's public Web server). Packets incoming on a DMZ interface -- whether from a LAN or external source -- are subject to a level of protection that is in between public and private interfaces in terms of restrictiveness.
  • RFC 1577: Specifies whether the IPoA protocol to be used complies with the IEFT specification named "RFC 1577 - Classical IP and ARP over ATM" (contact your ISP if unsure).
  • Lower interface: An IPoA interface must be associated with one or more ATM VCs that have been defined on the system. The ATM VC is also considered an interface--one that performs "lower level" functions (i.e., closer to hardware) than the IPoA interface. See Configuring the ATM VC for information about ATM VC interfaces.
  • Peer IP Address: The IP address of the remote computer you will be connecting to via the WAN interface.
  • Config IP Address and Net Mask: The IP address and network mask you want to assign to the interface.
  • Gateway Address: The external IP address that the ADSL/Ethernet router communicates with via the IPoA interface to gain access to the Internet. This is typically an ISP server.
  • Status: A green or red ball will display to indicate that the interface is currently up or down, respectively. You cannot manually enable or disable the interface; a down interface may indicate a problem with the DSL connection or with the remote peer computer.
  • Action: Icons you can click on to edit () or delete () the associated EOA interface.

Adding IPoA Interfaces

IPoA interfaces are created in two parts. First, you define basic properties of the interface:

  1. If the IPoA page is not already displaying, click the WAN tab and then click IPOA in the task bar.
  2. Click Add to display the IPoA Interface - Add page.
  3. Select the next available interface name from the IPoA Interface drop-down list.
  4. In the Config IP Address and Net Mask text boxes, type the address and mask that you want to assign to the IPoA interface.

    If you enable the DHCP option (in step 7 below), then the IP address you enter here will serve as a requested address; the DHCP server may assign another address if necessary.
  5. From the Interface Sec Type drop-down list, select the level of firewall security for the interface, as described above.
  6. In the RFC 1577 field, click the Yes radio button if the interface complies with the IETF specification of that name. 
  7. If the remote IPoA computer provides a DHCP server, you can click the Enable radio button in the Use DHCP field to have the IP address dynamically assigned from the server.
  8. If you want the IPoA interface to serve as the default route for your LAN, click the Enable radio button in the Default Route field. Only one WAN interface can serve as the default route.
  9. In the Gateway IP address, specify the gateway IP address provided by your ISP.
  10. Click Save Changes. A confirmation page will display to confirm your changes.
  11. Click Close to return to the IPoA page and view the new interface in the table.

Next, you map the interface to one or more VC interfaces.

  1. In the Action column of the interface table, click Map in the row associated with the newly created interface.
  2. In the IPoA Interface - Map page, select the lower interface(s) to associate with this IPoA interface, and click Add.
  3. Click Close when done. 

NOTE: If want your changes to be permanent, be sure to Write Settings to Flash.

To view all IPoA interfaces and their mappings to lower interfaces, display the IpoA Configuration page and click Map at the bottom of the page (not in the table).

The IPoA Interface - Global Map page displays all mappings. You can delete all mappings for an IPoA interface by clicking in the associated row. The IPoA interface is not deleted.