Network Check Control Plane Failure:

Question

Network Check Control Plane Failure:

hshekhar 0

[details] X_NHC_CONTROL_PLANE_UNREACHABLE: Instance failed network health check before bootstrapping with

fatal error: X_NHC_CONTROL_PLANE_UNREACHABLE 2 failed component(s): control_plane internet Retryable: true

Based on the failure results: List(entity: "centralindia.azuredatabricks.net" outcome: "unreachable" duration_sec: 263.28708 message: "curl: (28)

Connection timed out after 10001 milliseconds" last_error_code: 28 ,

entity: "www.databricks.com" outcome: "unreachable" duration_sec: 225.53181 message: "curl:

(28) Failed to connect to www.databricks.com port 443 after 7604 ms: Connection timed out" last_error_code: 28 )(OnDemand)

hshekhar 0 Reputation points

2026-03-05T07:22:11.37+00:00

How to resolve this?
SAI JAGADEESH KUDIPUDI 485 Reputation points Microsoft External Staff Moderator

2026-03-11T07:24:20.23+00:00
Hi **hshekhar,
**We are seeing network connectivity failures while the Databricks instance is trying to reach required control plane endpoints. The connections are timing out before the cluster bootstrapping completes.

To help us understand this better, we kindly request your help with the below details:

From where is the Databricks workspace being accessed? Is it through a private network (VPN / private connectivity) or directly from the public internet?

If a VPN is being used, could you please confirm: The type of VPN or private connectivity setup Whether outbound internet access is allowed through this network If private endpoints or private networking are configured, please confirm whether access to Databricks control plane URLs over port 443 is allowed. In case this is a public internet setup, we request you to please check from your side if any firewall, proxy, or network security rules are blocking outbound HTTPS traffic.

Your inputs will help us identify whether the issue is related to private networking restrictions or public network access and assist us in resolving this at the earliest.

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Your answer

hshekhar 0 Reputation points

2026-03-05T07:22:11.37+00:00

How to resolve this?
SAI JAGADEESH KUDIPUDI 485 Reputation points Microsoft External Staff Moderator

2026-03-11T07:24:20.23+00:00

Hi **hshekhar,
**We are seeing network connectivity failures while the Databricks instance is trying to reach required control plane endpoints. The connections are timing out before the cluster bootstrapping completes.

To help us understand this better, we kindly request your help with the below details:

From where is the Databricks workspace being accessed? Is it through a private network (VPN / private connectivity) or directly from the public internet?

If a VPN is being used, could you please confirm: The type of VPN or private connectivity setup Whether outbound internet access is allowed through this network If private endpoints or private networking are configured, please confirm whether access to Databricks control plane URLs over port 443 is allowed. In case this is a public internet setup, we request you to please check from your side if any firewall, proxy, or network security rules are blocking outbound HTTPS traffic.

Your inputs will help us identify whether the issue is related to private networking restrictions or public network access and assist us in resolving this at the earliest.

Answer 1

Hi ,

Thanks for reaching out to Microsoft Q&A.

This error means the Databricks cluster VM cannot reach the Databricks control plane over the internet, so the cluster fails the network health check before bootstrapping. Specifically, the compute node tried to connect to centralindia.azuredatabricks.net and Databricks at www.databricks.com, but both connections timed out on port 443 (HTTPS). This happens when outbound internet access is blocked from the Databricks worker node due to NSG rules, firewall restrictions, private network configuration, or missing NAT gateway/route to internet. To fix it, ensure the cluster subnet allows outbound HTTPS (443) to required databricks control plane endpoints and public internet, or configure NAT gateway/firewall allow rules if the workspace is deployed in a secure VNet injection setup. The error is retryable because once network connectivity is restored, the cluster can bootstrap successfully.

Please 'Upvote'(Thumbs-up) and 'Accept' as answer if the reply was helpful. This will be benefitting other community members who face the same issue.

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Network Check Control Plane Failure:

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