Connect to Azure Event Hubs via Private Endpoint from On Premise (Site-2-Site VPN)

bschroeter 6 Reputation points
2022-11-14T10:52:24.107+00:00

Hey

we are using a Site-2-Site VPN between Azure Vnet and OnPremise Network combined with a DNS Forwarder.
When deploying a Azure Event Hubs Namespace (Standard Tier) Private Endpoint into the connected Vnet the DNS doesn't get resolved to the private IP and we can't send messages from OnPremise to the Event Hub.
Other Endpoints for example like StorageAccount or Synapse get resolved and can be used correctly.
Is it possible to use the Event Hub Entpoint from OnPremise in combination with Site-2-Site VPN?

Thanks and best regards

Azure Event Hubs
Azure Event Hubs
An Azure real-time data ingestion service.
593 questions
Azure Private Link
Azure Private Link
An Azure service that provides private connectivity from a virtual network to Azure platform as a service, customer-owned, or Microsoft partner services.
486 questions
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2 answers

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  1. bschroeter 6 Reputation points
    2022-12-06T11:32:47.13+00:00

    Thanks for your help @Bas Pruijn , @Bruno Lucas , @BhargavaGunnam-MSFT !
    The problem was a firewall misconfiguration on premise for the servicebus domain names. After fixing the DNS got resolved correctly to private IP and the eventhub could be reached from on premise through private endpoint

    1 person found this answer helpful.

  2. Bas Pruijn 951 Reputation points
    2022-11-15T12:43:13.437+00:00

    I have seen similar issues in the past. Usually this is when the private DNS zone is not correctly linked to the VNET where your VPN Gateway is hosted. When you create a new service that uses private endpoints, it creates a new privatelink private DNS zone. This new privatelink DNS zone is not automatically linked to your VPN Gateway network, and therefor you might not be able to connect.

    You can try this by doing a nslookup <FQDN of your Eventhub> <ip address of your DNS forwarder>

    This should result in a private IP address being returned. If your privatelink DNS zones are not linked correctly, you will find the public IP address of your eventhub.