Configure a Loopback Interface

Let us learn to configure a loopback interface.
Loopback is a logical, virtual interface used to emulate a WAN port to provide LAN functionality. You can free up a physical port previously used for LAN/WAN configuration by designating a loopback interface. You can configure a maximum of four loopback interfaces per device.
ION devices on
versions 4.5.3 or later
at a site, support loopback interface. A loopback interface can only be used as a WAN port on interfaces with no hardware bypass circuitry. Interfaces with no hardware bypass circuitry per device are as follows:
  • ION 1000—All ports.
  • ION 1200—All ports.
  • ION 2000—Ports 1–3.
  • ION 7000—Ports 1–4, 9–14.
  • Virtual IONs—All non-controller ports.
A loopback interface may be brought up or down administratively and may not contain any sub-interfaces or IP configurations.
  • You can update or delete a loopback interface. However, you cannot delete if it is part of a bypass pair.
  • Decouple a port coupled with another port before a loopback interface can be coupled to create a bypass pair.
  • The only valid option in the Use These Ports For drop-down is Private Layer 2 for a bypass pair that is made up of a physical LAN port and a loopback interface as the WAN port.
  • The network policy rules assigned to such a site must not have any rules using the Direct on private WAN path. Valid paths are Direct on public or VPN on public. Traffic is dropped if a direct on private path is used.
  1. From
    Claimed Devices
    select a device and click
    Configure the device
  2. Select the
  3. On the interface configuration page for a device, click the
    add icon to add a loopback interface and select
  4. For
    Admin Up
    , select
    to administratively bring the interface up or down.
  5. Enter a
    and select
    Create Loopback
    The system assigns a default loopback ID to the interface. A confirmation message displays that the loopback interface is successfully created.
  6. Next, select a port to be configured with a loopback interface.
  7. For
    Admin Up
    , select
    to administratively bring the interface up or down. The default is Yes.
  8. (Optional)
    Enter a
  9. From the
    Interface Type
    drop-down, select
    Bypass Pair
  10. From the
    Pair With
    drop-down, select the Loopback Interface.
    A confirmation message displays.
  11. Select
    to create a bypass pair with the loopback interface successfully.
    A confirmation message displays the port's successful creation and the loopback interface.
  12. For
    Use These Ports For
    , select
    Private L2
    from the drop-down.
    This is the only valid option for a bypass pair that is made of a physical LAN port and a loopback interface for the WAN port.
  13. Select the
    Circuit Label
    from the drop-down.
  14. (Optional)
    If you choose
    Copy Settings from Another Port
    , select the bypass pair to copy the settings. If not, you may leave it blank.
  15. Similar to configuring bypass pairs, for
    Attached Networks
    , enter a
    IP Address at Router
    , optional
    Network Context
    , and toggle the scope tp
  16. Save Bypass Pair
    The port and the loopback interface are displayed under Interfaces.

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