New notification hub not available for use due to DNS issue

Question

New notification hub not available for use due to DNS issue

Jonathan Brenchley 25

When trying to create a notification hub via the portal, the deployment get stuck in a loop at the point "Get Namespace Resource".

After a support call, we identified that creating the namespace first using the CLI and then adding the hub appeared to succeed. However, the hub that is created is not accessible due to a DNS issue. Presumably that is what caused the portal deployment to become stuck in a loop.

When attempting to access REST endpoints the error is "The remote name could not be resolved“

URLs in this form: https://<namespace>.servicebus.windows.net/<hubname>/registrations/?api-version=2015-01

gives "unauthorised" for an operating hub, but "The remote name could not be resolved" for the new hub

ramana murthy 0 Reputation points

2026-07-17T16:20:38.4733333+00:00
Verify that the Notification Hub namespace is in the Succeeded provisioning state.

Wait 15–30 minutes and test the endpoint again.

Confirm the namespace name and endpoint URL are correct.

Check the Azure Service Health dashboard for any Notification Hubs or DNS-related incidents in your region.

If the issue persists, open an Azure Support request because this is likely a service-side issue rather than an application issue.
Aditya N 3,810 Reputation points Microsoft External Staff Moderator

2026-07-17T16:52:14.9233333+00:00

Hello @Jonathan Brenchley

Thank you for reaching out Microsoft Q&A. We're looking into it, we'll get back to you shortly.
Jonathan Brenchley 25 Reputation points

2026-07-19T09:26:37.7933333+00:00

I am still getting a DNS failure so will update the support case
Aditya N 3,810 Reputation points Microsoft External Staff Moderator

2026-07-26T00:44:52.0533333+00:00

Hello @Jonathan Brenchley

Please could you provide the details which are requested in private message.

2 answers

Your answer

ramana murthy 0 Reputation points

2026-07-17T16:20:38.4733333+00:00

Verify that the Notification Hub namespace is in the Succeeded provisioning state.

Wait 15–30 minutes and test the endpoint again.

Confirm the namespace name and endpoint URL are correct.

Check the Azure Service Health dashboard for any Notification Hubs or DNS-related incidents in your region.

If the issue persists, open an Azure Support request because this is likely a service-side issue rather than an application issue.
Aditya N 3,810 Reputation points Microsoft External Staff Moderator

2026-07-17T16:52:14.9233333+00:00

Hello @Jonathan Brenchley

Thank you for reaching out Microsoft Q&A. We're looking into it, we'll get back to you shortly.
Jonathan Brenchley 25 Reputation points

2026-07-19T09:26:37.7933333+00:00

I am still getting a DNS failure so will update the support case
Aditya N 3,810 Reputation points Microsoft External Staff Moderator

2026-07-26T00:44:52.0533333+00:00

Hello @Jonathan Brenchley

Please could you provide the details which are requested in private message.

Answer 1

Jonathan Brenchley 25

The issue appeared to be a delay in DNS propagation within Microsoft. After creating a notification namespace and hub via CLI, I had to wait ~48 hours before the DNS names started resolving correctly. Until then, the hub and namespace were reported as deployed successfully, but did not work.

Michal Hoffmann 0 Reputation points

2026-08-13T14:01:41.5266667+00:00

Thank you for sharing that - I had just the same problem, then I found your answer, and yes, after over a day it started working (I was checking with nslookup from time to time)

Answer 2

The URI format is correct. Notification Hubs data-plane operations use the namespace hostname under servicebus.windows.net, so DNS belongs to the namespace, not the individual hub. “Remote name could not be resolved” occurs before authentication and points to incomplete namespace provisioning or DNS registration, not a SAS-key problem.

Inspect namespace resource properties: provisioningState, status, enabled, and serviceBusEndpoint. Test the exact hostname returned by serviceBusEndpoint using two public DNS resolvers. A 401 from an unauthenticated request is useful: it proves DNS, TCP, and TLS work, leaving authorization as the expected next step.

If that endpoint still does not resolve after the namespace reports Succeeded, capture resource ID, region, creation time, and deployment correlation ID. Recreate the namespace with a different globally unique name if disposable. Otherwise update the support case and request Notification Hubs namespace DNS-registration repair. Recreating hubs or rotating keys inside the same namespace will not fix missing namespace DNS.