Setting Up and Enabling Loopbacks

Updated
  • Updated on Jan 27, 2026
  • Published on Jan 7, 2022
  • 2 minute(s) read
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To set up a local loopback, complete the following tasks:

  • Create a filter that defines the matching criteria for captured traffic (required for Custom loopbacks only).
  • Create the loopback.

To set up a local loopback

  1. Choose Loopback ▶ Configuration.

    The page displays a summary of the configured OAM loopback instances.

  2. Do one of the following:

    • Click Add to create an instance.
    • Click an instance Name to edit its settings.

  3. Enter values in the required fields, and then click Apply.

For more information about specific parameters, see the following table.

Note: For a local loopback, only the fields listed in the following table are required. Leave all other fields at their default settings.

Loopback (Loopback ▶ Configuration)

Parameter Description
Name OAM Loopback instance name, as defined on this page.
Device Name of the remote device to which the loopback applies.
Port Port on the remote device to which the loopback applies. Both UNI and NNI ports are supported.
State Current loopback state (Enabled or Disabled).

Default: Disabled.
Loopback enable Select to activate this loopback instance, and then select a Type.

Note: After a Sensor Control reboot or a firmware upgrade or downgrade, the system disables any previously enabled loopback.
Type Loopback type:
  • Custom: Loops back traffic that matches the user-defined filter (Filter type and related fields).
Filter type Filter type for loopback traffic:
  • L2 filter
  • IPv4 filter
  • IPv6 filter
L2 filter L2 filter to apply to loopback traffic when Filter type is L2 filter. All L2 filter parameters are supported.
IPv4 filter IPv4 filter to apply to loopback traffic when Filter type is IPv4 filter. All IPv4 filter parameters are supported.
IPv6 filter IPv6 filter to apply to loopback traffic when Filter type is IPv6 filter. All IPv6 filter parameters are supported.
Actions One or more actions:
  • Swap MAC addresses: Swaps the source and destination MAC addresses.
  • Swap IP addresses: Swaps the source and destination IP addresses.
  • Swap TCP/UDP ports: Swaps the source and destination TCP/UDP ports.
Drop opposite traffic Select to drop traffic that enters the device on the opposite port. If you do not select this option, the system restores opposite traffic five seconds after the loopback times out.

Note: Selecting this option interrupts the Ethernet service in one direction.

Remote loopback enable

Parameter Description
JDSU/Acterna™ Select to indicate that the remote loopback is controlled by a JDSU/Acterna™ device.
Enable discovery loop commands Select to accept JDSU/Acterna™ discovery loopback commands.
Loop up timeout Timeout period after the unit receives the Loop Up command before it initiates the JDSU loopback tests.

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