Network Fabric read-only commands for troubleshooting

Article
04/16/2024

Troubleshooting network devices is a critical aspect of effective network management. Ensuring the health and optimal performance of your infrastructure requires timely diagnosis and resolution of issues. In this guide, we present a comprehensive approach to troubleshooting Azure Operator Nexus devices using read-only (RO) commands.

Understanding read-only commands

RO commands serve as essential tools for network administrators. Unlike read-write (RW) commands that modify device configurations, RO commands allow administrators to gather diagnostic information without altering the device's state. These commands provide valuable insights into the device's status, configuration, and operational data.

Read-only diagnostic API

The read-only diagnostic API enables users to execute show commands on network devices via an API call. This efficient method allows administrators to remotely run diagnostic queries across all network fabric devices. Key features of the read-only diagnostic API include:

Efficiency - Execute show commands without direct access to the device console.
Seamless Integration with AZCLI: Users can utilize the regular Azure Command-Line Interface (AZCLI) to pass the desired "show command." The API then facilitates command execution on the target device, fetching the output.
JSON Output: Results from the executed commands are presented in JSON format, making it easy to parse and analyze.
Secure Storage: The output data is stored in the customer-owned storage account, ensuring data security and compliance.

By using the read-only diagnostic API, network administrators can efficiently troubleshoot issues, verify configurations, and monitor device health across their Azure Operator Nexus devices.

Prerequisites

To use Network Fabric read-only commands, complete the following steps:

Provision the Nexus Network Fabric successfully.
Generate the storage URL.

Refer to Create a container to create a container.

Note

Enter the name of the container using only lowercase letters.

Refer to Generate a shared access signature to create the SAS URL of the container. Provide Write permission for SAS.

Note

SAS URLs are short lived. By default, it is set to expire in eight hours. If the SAS URL expires, then the fabric must be re-patched.
Provide the storage URL with WRITE access via a support ticket.

Note

The Storage URL must be located in a different region from the Network Fabric. For instance, if the Fabric is hosted in East US, the storage URL should be outside of East US.

Command restrictions

To ensure security and compliance, RO commands must adhere to the following specific rules:

Only absolute commands should be provided as input. Short forms and prompts aren't supported. For example:
- Enter show interfaces Ethernet 1/1 status
- Don't enter sh int stat or sh int e1/1 status
Commands must not be null, empty, or consist only of a single word.
Commands must not include the pipe (|) character.
Show commands are unrestricted, except for the high CPU intensive commands specifically referred to in this list of restrictions.
Commands must not end with tech-support, agent logs, ip route, or ip route vrf all.
Only one show command at a time can be used on a specific device.
You can run the show command on another CLI window in parallel.
You can run a show command on different devices at the same time.

Troubleshoot using read-only commands

To troubleshoot using read-only commands, follow these steps:

Open a Microsoft support ticket. The support engineer makes the necessary updates.

Execute the following Azure CLI command:

az networkfabric device run-ro --resource-name "<NFResourceName>" --resource-group "<NFResourceGroupName>" --ro-command "show version"

Expected output:

{ }

Enter the following command:

az networkfabric device run-ro --resource-group Fab3LabNF-6-0-A --resource-name nffab3-6-0-A-AggrRack-CE1 --ro-command "show version" --no-wait --debug

The following (truncated) output appears. Copy the URL through private preview. This portion of the URL is used in the following step to check the status of the operation.

https://management.azure.com/subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/providers/Microsoft.ManagedNetworkFabric/locations/EASTUS2EUAP/operationStatuses/59fdc0c8-eeb1-4258-9163-3cf096490148*A9E6DB3DF5C58D67BD395F7A608C056BC8219C392CC1CE0AD22E4C36D70CEE5C?api-version=2022-01-15-privatepreview***&t=638485032018035520&c=MIIHHjCCBgagAwIBAgITfwKWMg6goKCq4WwU2AAEApYyDjANBgkqhkiG9w0BAQsFADBEMRMwEQYKCZImiZPyLGQBGRYDR0JMMRMwEQYKCZImiZPyLGQBGRYDQU1FMRgwFgYDVQQDEw9BTUUgSW5mcmEgQ0EgMDIwHhcNMjQwMTMwMTAzMDI3WhcNMjUwMTI0MTAzMDI3WjBAMT4wPAYDVQQDEzVhc3luY29wZXJhdGlvbnNpZ25pbmdjZXJ0aWZpY2F0ZS5tYW5hZ2VtZW50LmF6dXJlLmNvbTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBALMk1pBZQQoNY8tos8XBaEjHjcdWubRHrQk5CqKcX3tpFfukMI0_PVZK-Kr7xkZFQTYp_ItaM2RPRDXx-0W9-mmrUBKvdcQ0rdjcSXDek7GvWS29F5sDHojD1v3e9k2jJa4cVSWwdIguvXmdUa57t1EHxqtDzTL4WmjXitzY8QOIHLMRLyXUNg3Gqfxch40cmQeBoN4rVMlP31LizDfdwRyT1qghK7vgvworA3D9rE00aM0n7TcBH9I0mu-96JE0gSX1FWXctlEcmdwQmXj_U0sZCu11_Yr6Oa34bmUQHGc3hDvO226L1Au-QsLuRWFLbKJ-0wmSV5b3CbU1kweD5LUCAwEAAaOCBAswggQHMCcGCSsGAQQBgjcVCgQaMBgwCgYIKwYBBQUHAwEwCgYIKwYBBQUHAwIwPQYJKwYBBAGCNxUHBDAwLgYmKwYBBAGCNxUIhpDjDYTVtHiE8Ys-

Check the status of the operation programmatically using the following Azure CLI command:

az rest -m get -u "<Azure-AsyncOperation-endpoint url>"

The operation status indicates if the API succeeded or failed, and appears similar to the following output:

https://management.azure.com/subscriptions/xxxxxxxxxxx/providers/Microsoft.ManagedNetworkFabric/locations/EASTUS/operationStatuses/xxxxxxxxxxx?api-version=20XX-0X-xx-xx

View and download the generated output file. Sample output is shown here.

 {
 "architecture": "x86_64",
  "bootupTimestamp": 1701940797.5429916,
  "configMacAddress": "00:00:00:00:00:00",
  "hardwareRevision": "12.05",
  "hwMacAddress": "c4:ca:2b:62:6d:d3",
  "imageFormatVersion": "3.0",
  "imageOptimization": "Default",
  "internalBuildId": "d009619b-XXXX-XXXX-XXXX-fcccff30ae3b",
  "internalVersion": "4.30.3M-33434233.4303M",
  "isIntlVersion": false,
  "memFree": 3744220,
  "memTotal": 8107980,
  "mfgName": "Arista",
  "modelName": "DCS-7280DR3-24-F",
  "serialNumber": "JPAXXXX1LZ",
  "systemMacAddress": "c4:ca:2b:62:6d:d3",
  "uptime": 8475685.5,
  "version": "4.30.3M"
 }

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