Configuring a breakout port

On 7220 IXR-D3 systems, the QSFP28 connector ports (ports 1/3-1/33) can operate in breakout mode. Four breakout ports, each operating at 25G, can be configured on each QSFP28 connector port operating in breakout mode.

In the Fabric Services System, you can enable breakout mode for supporting ports as part of Edge Link Interface configuration for a fabric intent.

When a port is configured in breakout mode, the original port itself can no longer be selected as a sub-interface for a workload intent, nor can it be made part of a LAG. However each of the broken-out sub-ports derived from it can:

  • participate in a LAG; however a LAG cannot include a mixture of regular ports and broken-out sub-ports; all of the ports in a LAG must be of one type of the other.
  • be selected as a sub-interface for a workload intent.

In lists of ports in the UI, the system displays the broken-out ports as a group of four sub-ports; for example, port 1/3 in breakout mode displays as ports 1/3/1 through 1/3/4.

You can un-configure breakout mode for a port, but only if none of the broken-out ports are currently members of a LAG or functioning as sub-interfaces.

Note:

LAG configuration is not supported on the initial version of a fabric intent. To configure a LAG, you must first save and deploy Version 1.0 of the fabric intent, and then create a new version of the intent (as described in Creating a new version of a fabric intent). You can configure LAGs for Version 2.0 and greater of a fabric intent.

To configure a port in breakout mode, do the following:

  1. Choose one of the following:
    • If you are configuring ports for a fabric intent that is already deployed, begin by creating a new candidate version of the existing fabric intent as described in Creating a new version of a fabric intent. Then go to step 2.
    • If you are configuring breakout ports for Version 2.0 or greater of a fabric intent that has not yet been deployed, go to step 2.
  2. Open the fabric intent as described in Viewing a fabric intent.
  3. From the View drop-down, select Edge-Links.
  4. In the list of edge links, select a port by checking the box at the left edge of its row.
  5. At the right edge of the row for the selected port, click the More actions icon () and select Open.
  6. Click the Breakout Mode toggle to enable Breakout Mode for the port.
    The UI displays the following new properties for the port in read-only mode:
    • Num Channels (number of channels), set to 4.
    • Channel Speed, set to 25.
  7. Click SAVE.