Fabrics

A fabric is a collection of switches specific to one organization, and each switch is specific to a single fabric. A fabric is the configuration and monitoring domain; users configure fabrics, not individual switches. A fabric is also a blueprint to which physical devices are bound and interconnected. The blueprint helps ensure the adhereance to all physical and logical designs.

These are some of the things that you define in a fabric blueprint:​

  • Switch model​
  • Number of spine switches and leaf switches
  • Through which port the switches are connected​
  • VRF instance, VNI, and VLAN configuration​
  • Routing configuration​
  • Target software release for the switches in the fabric​

Create a new fabric

When you have created a new organization or need to add a fabric to an existing organization, you can use the Blueprint Designer in the Cisco Nexus Hyperfabric to create a blueprint for the new fabric.

Follow these steps to create a new fabric.

Step 1

Select Fabrics.

Step 2

Click + Add new fabric.

Add new fabric

Step 3

Fill out the dialog box as necessary.

  1. For Fabric name, enter a unique name from 3 to 120 characters. The name can contain a hyphen (-), but no other special characters.

  2. For Description, enter a description of the fabric.

  3. For Address, enter the physical address where the fabric is located.

  4. For Location, enter additional location information about the fabric.

  5. For Spines, select the quantity of switches, the airflow, and the PSU PID. Cisco Nexus Hyperfabric selects the fan PID automatically based on what you select for the airflow.

  6. For Leaves, select the quantity of switches, the airflow, and the PSU PID. Cisco Nexus Hyperfabric selects the fan PID automatically based on what you select for the airflow.

To design a single-switch fabric or a mesh fabric, select only leaf switches. If you select one or more spine switches, select two or more switches to create a spine-and-leaf topology.

As you make your switch choices, Cisco Nexus Hyperfabric updates the topology.

Step 4

Click either Save fabric and skip cabling for now or Save fabric and add cabling.

If you do not want to add the cabling at this time, click Save fabric and skip cabling for now. Cisco Nexus Hyperfabric adds a tile for the new fabric. This example shows a spine-and-leaf fabric with two spine switches and two leaf switches:

New fabric tile

If you want to add the cabling now, click Save fabric and add cabling, which opens the Auto Cabling dialog box. Follow these substeps.

  1. For Order, enter the number of links that you want to have between each switch pair.

    In most cases, you can use the default of 1.

  2. For Pluggable, enter the product ID of the optic. Optionally, select one of the optics from the table at the bottom of the dialog box to fill in the field based on what you chose. You can use the Search field and Plug type, Speed, and Cable type drop-down lists to filter the table.

  3. Click Save at the bottom of the dialog box.

    The Auto Cabling dialog box closes and the Fabric connects table now shows how you should connect the switches.

Cisco Nexus Hyperfabric adds a tile for the new fabric. The tile shows "Pending changes" because you must review and push the cabling configuration change. For the procedure, see Finish and commit the design. This example shows a spine-and-leaf fabric with two spine switches and two leaf switches:

Pending changes

Change the fabric mode

Cisco Nexus Hyperfabric has two fabric modes: classic and beta. You must use the classic mode for non-AI clusters fabrics and beta mode for AI clusters fabrics. Any fabric that you created before the introduction of AI clusters automatically uses the classic mode. You can see all fabrics of either mode from the Fabrics and Inventory pages. However, you must change Cisco Nexus Hyperfabric to the same mode as the fabric to view that fabric's details and modify the fabric.

If you attempt to view the details of a fabric and Cisco Nexus Hyperfabric is in the wrong mode, Cisco Nexus Hyperfabric asks if you want to switch to the correct mode. You can also manually change the mode, as described in this procedure.

Follow these steps to change the fabric mode.

Step 1

Select your username in the upper right of the GUI.

Fabric mode

Step 2

For Fabric mode, select the toggle to change between Classic and Beta.

Modifying fabrics

If you have administrator or read-write access to the organization, you can modify the design of an existing fabric on the Fabrics page. You can make changes to the fabric blueprint at any stage: from an undeployed fabric design to an installed and running fabric.

The Fabrics blueprint page operates in one of two modes:

  • Edit mode—This is the default mode for a user with administrator or read-write access. All fabric edit options are exposed.
  • Running mode—This is the default mode for a user with read-only access. Settings and status are displayed, but no edit options are exposed. You can switch to edit mode only if you have administrator or read-write access.
 Note

All configuration procedures in this document assume that you are logged in with administrator or read-write access, and that the menus are in edit mode.

Modify a fabric

This procedure provides the typical workflow for making fabric configuration changes.

Follow these steps to modify a fabric.

Step 1

Select Fabrics, then click the fabric that you want to configure.

Step 2

If the fabric is not in the edit mode, click Switch to edit mode.

Step 3

Make your changes.

 Note

Your changes are not applied to the fabric until you review, commit, and push them.

Step 4

When you're ready to apply your changes, click Review configuration.

Review configuration

In the Review configuration page, you can view a list of brief descriptions of the changes since the last push, including the author's ID and the date and time when the change was saved.

Step 5

When you have reviewed the changes and are ready to apply them, click Comment and push.

Step 6

In the Comment before pushing configuration dialog box, enter the reason for the change.

Step 7

Click Push configuration.

Step 8

View the status of your changes.

On the Fabrics blueprint page, view the fabric card to see the status of the pushed changes. Your changes may take some time to apply or they might generate red assertions. For example, if you push changes to an installed and running fabric, and the changes conflict with the physical cabling of the fabric, an assertion is raised.

Modify a fabric topology

To add or remove switches, or to otherwise modify the topology of an existing fabric, navigate to the Fabrics page. In this menu, you can define the blueprint for the fabric. See the terminology section in the Cisco Nexus Hyperfabric Getting Started document. When you modify the fabric, the Nexus Hyperfabric creates a new blueprint.

Follow these steps to modify a fabric topology.

Step 1

Select Fabrics, then click the fabric that you want to modify.

Step 2

If the fabric is not in the edit mode, click Switch to edit mode.

Step 3

In the Topology area, click Edit fabric.

Step 4

In the Edit fabric dialog box, set the properties as desired.

  1. Enter the fabric name.

  2. (Optional) Enter a description, address, and location of the fabric.

  3. Select the number of spine switches and leaf switches.

    For a single-switch fabric or a mesh fabric, select only leaf switches. If you select one or more spine switches, select two or more leaf switches to create a spine and leaf topology. As you make your switch selections, the topology diagram changes to display the resulting fabric.

Step 5

Click Save.

Considerations for modifying a fabric topology

Removing a switch or a cable from a fabric topology impacts traffic going through the interface that you removed from the fabric. Adding a switch or a cable does not impact traffic.

Finish and commit the design

Your changes are not applied to the fabric until you review, commit, and push them.

Follow these steps to finish and commit the design.

Step 1

Click Review configuration.

Review configuration button

Step 2

Verify your changes in the review list.

Step 3

Click Comment and push.

Step 4

In the Comment before pushing configuration dialog box, enter the reason for the change.

Step 5

Click Push configuration.

If you bound any devices as part of this push, the outline color of the device icons indicates the assertions for the devices. The devices should have a green outline, which indicates that there are no issues. A yellow outline indicates the device has an unexpected condition and there are issues detected, but the issues should not cause operation disruption. A red outline indicates the device has an unexpected condition and there are issues detected that can cause operation disruption; you should investigate the issues.

Bound switches

View Event viewer

Event viewer displays the time series for events such as failed assertions, resolved assertions, and configuration events for a device.

Step 1

Select Fabrics, then select Fabric > Event viewer.

Step 2

The Event Viewer area displays the time series for failed assertions, resolved or cleared assertions, and configuration events. Configuration events are displayed separately as a line graph. From the drop-down list, select the time period. By default, Last hour is chosen.

Step 3

Use the Types drop-down list, to filter the event types.

 Note

Candidate comments displays comments you enter when you push a configuration and are only applicable for configuration events.

Step 4

In the Description column, click Configuration pushed to view additional details.