| title | Configure IP Firewall Rules for Azure Event Hubs Namespaces | ||||||
|---|---|---|---|---|---|---|---|
| description | Learn how to configure IP firewall rules for Azure Event Hubs namespaces to restrict access to specific IP addresses and enhance your network security. | ||||||
| ms.topic | how-to | ||||||
| ms.date | 01/30/2026 | ||||||
| ms.custom |
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By default, users can access Event Hubs namespaces from the internet as long as the request comes with valid authentication and authorization. By using the IP firewall, you can restrict access to only a set of IPv4 and IPv6 addresses or address ranges in CIDR (Classless Inter-Domain Routing) notation.
This feature is helpful in scenarios where Azure Event Hubs should be accessible only from certain well-known sites. Firewall rules enable you to configure rules to accept traffic originating from specific IPv4 and IPv6 addresses. For example, if you use Event Hubs with Azure Express Route, you can create a firewall rule to allow traffic from only your on-premises infrastructure IP addresses.
You specify IP firewall rules at the Event Hubs namespace level. The rules apply to all connections from clients using any supported protocol. The Event Hubs namespace rejects any connection attempt from an IP address that doesn't match an allowed IP rule as unauthorized. The response doesn't mention the IP rule. IP firewall rules are applied in order, and the first rule that matches the IP address determines the accept or reject action.
- This feature isn't supported in the basic tier.
- When you turn on firewall rules for your Event Hubs namespace, the firewall blocks incoming requests by default, unless requests originate from a service operating from allowed public IP addresses. Blocked requests include the requests from other Azure services, from the Azure portal, from logging and metrics services, and so on. As an exception, you can allow access to Event Hubs resources from certain trusted services even when the IP filtering is enabled. For a list of trusted services, see Trusted Microsoft services.
- Specify at least one IP firewall rule or virtual network rule for the namespace to allow traffic only from the specified IP addresses or subnet of a virtual network. If there are no IP and virtual network rules, users can access the namespace over the public internet (by using the access key).
When creating a namespace, you can either allow public only (from all networks) or private only (only via private endpoints) access to the namespace. Once you create the namespace, you can allow access from specific IP addresses or from specific virtual networks (by using network service endpoints).
To enable public access, select Public access on the Networking page of the namespace creation wizard.
:::image type="content" source="./media/event-hubs-firewall/create-namespace-public-access.png" alt-text="Screenshot showing the Networking page of the Create namespace wizard with Public access option selected." lightbox="./media/event-hubs-firewall/create-namespace-public-access.png":::
After you create the namespace, select Networking in the left menu of the Event Hubs Namespace page.
By default, Public network access is enabled for the namespace for all networks.
:::image type="content" source="./media/event-hubs-firewall/public-network-access.png" alt-text="Screenshot showing the Networking page of the Event Hubs namespace with Public network access enabled." lightbox="./media/event-hubs-firewall/public-network-access.png":::
This option enables public access from all networks by using an access key. The namespace accepts connections from any IP address (using the access key).
The next section provides you details on configuring IP firewall rules to specify the IP addresses from which the access is allowed.
This section shows you how to use the Azure portal to create IP firewall rules for an Event Hubs namespace.
-
Navigate to your Event Hubs namespace in the Azure portal.
-
Select Networking under Settings on the left menu.
-
On the Networking page, select Manage under Public network access.
:::image type="content" source="./media/event-hubs-firewall/manage-public-network-access.png" alt-text="Screenshot showing the Public access page with Manage button highlighted." lightbox="./media/event-hubs-firewall/enable-selected-networks.png":::
-
On the Public network access page, in the Default action section, select Enable from selected networks to allow access from only specified IP addresses.
:::image type="content" source="./media/event-hubs-firewall/enable-selected-networks.png" alt-text="Screenshot showing the Public network access page with Enable from selected networks option selected." lightbox="./media/event-hubs-firewall/enable-selected-networks.png":::
[!IMPORTANT] If you choose Selected networks, add at least one IP firewall rule or a virtual network that has access to the namespace. Choose Disabled if you want to restrict all traffic to this namespace over private endpoints only.
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In the IP Addresses section, select Add your client IP address option to give your current client IP the access to the namespace.
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For address range, enter specific IPv4 or IPv6 addresses or address ranges in CIDR notation.
[!IMPORTANT] We recommend that you add IPv6 addresses to the list of allowed IP addresses now so that your clients don't break when the service eventually switches to supporting only IPv6.
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In the Exception section, specify whether you want to allow trusted Microsoft services to access this resource. See Trusted Microsoft services for details.
:::image type="content" source="./media/event-hubs-firewall/firewall-selected-networks-trusted-access-disabled.png" lightbox="./media/event-hubs-firewall/firewall-selected-networks-trusted-access-disabled.png" alt-text="Firewall section highlighted in the Public access tab of the Networking page.":::
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Select Save on the toolbar to save the settings. Wait for a few minutes for the confirmation to show up on the portal notifications.
[!NOTE] To restrict access to specific virtual networks, see Allow access from specific networks.
[!INCLUDE event-hubs-trusted-services]
Important
The Firewall feature isn't supported in the basic tier.
The following Resource Manager template enables adding an IP filter rule to an existing Event Hubs namespace.
The ipMask in the template is a single IPv4 address or a block of IP addresses in CIDR notation. For example, in CIDR notation 70.37.104.0/24 represents the 256 IPv4 addresses from 70.37.104.0 to 70.37.104.255, with 24 indicating the number of significant prefix bits for the range.
Note
The default value of the defaultAction is Allow. When adding virtual network or firewalls rules, make sure you set the defaultAction to Deny.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"namespace_name": {
"defaultValue": "contosoehub1333",
"type": "String"
}
},
"variables": {},
"resources": [
{
"type": "Microsoft.EventHub/namespaces",
"apiVersion": "2022-01-01-preview",
"name": "[parameters('namespace_name')]",
"location": "East US",
"sku": {
"name": "Standard",
"tier": "Standard",
"capacity": 1
},
"properties": {
"minimumTlsVersion": "1.2",
"publicNetworkAccess": "Enabled",
"disableLocalAuth": false,
"zoneRedundant": true,
"isAutoInflateEnabled": false,
"maximumThroughputUnits": 0,
"kafkaEnabled": true
}
},
{
"type": "Microsoft.EventHub/namespaces/authorizationrules",
"apiVersion": "2022-01-01-preview",
"name": "[concat(parameters('namespace_name'), '/RootManageSharedAccessKey')]",
"location": "eastus",
"dependsOn": [
"[resourceId('Microsoft.EventHub/namespaces', parameters('namespace_name'))]"
],
"properties": {
"rights": [
"Listen",
"Manage",
"Send"
]
}
},
{
"type": "Microsoft.EventHub/namespaces/networkRuleSets",
"apiVersion": "2022-01-01-preview",
"name": "[concat(parameters('namespace_name'), '/default')]",
"location": "East US",
"dependsOn": [
"[resourceId('Microsoft.EventHub/namespaces', parameters('namespace_name'))]"
],
"properties": {
"publicNetworkAccess": "Enabled",
"defaultAction": "Deny",
"virtualNetworkRules": [],
"ipRules": [
{
"ipMask": "10.1.1.1",
"action": "Allow"
},
{
"ipMask": "11.0.0.0/24",
"action": "Allow"
},
{
"ipMask": "172.72.157.204",
"action": "Allow"
}
]
}
}
]
}To deploy the template, follow the instructions for Azure Resource Manager.
Important
If you don't add any IP or virtual network rules, all traffic flows into the namespace even if you set the defaultAction to deny. Users can access the namespace over the public internet (by using the access key). To allow traffic only from the specified IP addresses or subnet of a virtual network, specify at least one IP rule or virtual network rule for the namespace.
Use az eventhubs namespace network-rule-set add, list, update, and remove commands to manage IP firewall rules for an Event Hubs namespace.
Use the Set-AzEventHubNetworkRuleSet cmdlet to add one or more IP firewall rules. An example from the article:
$ipRule1 = New-AzEventHubIPRuleConfig -IPMask 2.2.2.2 -Action Allow
$ipRule2 = New-AzEventHubIPRuleConfig -IPMask 3.3.3.3 -Action Allow
$virtualNetworkRule1 = New-AzEventHubVirtualNetworkRuleConfig -SubnetId '/subscriptions/subscriptionId/resourcegroups/myResourceGroup/providers/Microsoft.Network/virtualNetworks/myVirtualNetwork/subnets/default'
$networkRuleSet = Get-AzEventHubNetworkRuleSet -ResourceGroupName myResourceGroup -NamespaceName myNamespace
$networkRuleSet.IPRule += $ipRule1
$networkRuleSet.IPRule += $ipRule2
$networkRuleSet.VirtualNetworkRule += $virtualNetworkRule1
Set-AzEventHubNetworkRuleSet -ResourceGroupName myResourceGroup -NamespaceName myNamespace -IPRule $ipRule1,$ipRule2 -VirtualNetworkRule $virtualNetworkRule1,$virtualNetworkRule2,$virtualNetworkRule3
For API versions 2021-01-01-preview and earlier, the default value of the defaultAction property is Deny. However, the service doesn't enforce the deny rule unless you set IP filters or virtual network rules. If you don't set any IP filters or virtual network rules, the service treats the default action as Allow.
From API version 2021-06-01-preview onwards, the default value of the defaultAction property is Allow, which accurately reflects the service-side enforcement. If you set the default action to Deny, the service enforces IP filters and virtual network rules. If you set the default action to Allow, the service doesn't enforce IP filters and virtual network rules. The service remembers the rules when you turn them off and then back on again.
API version 2021-06-01-preview onwards also introduces a new property named publicNetworkAccess. If you set this property to Disabled, operations are restricted to private links only. If you set it to Enabled, operations are allowed over the public internet.
For more information about these properties, see Create or Update Network Rule Set and Create or Update Private Endpoint Connections.
Note
None of the preceding settings bypass validation of claims through SAS or Microsoft Entra authentication. The authentication check always runs after the service validates the network checks that the defaultAction, publicNetworkAccess, and privateEndpointConnections settings configure.
Azure portal always uses the latest API version to get and set properties. If you configured your namespace by using 2021-01-01-preview and earlier versions with the defaultAction set to Deny, and you specified zero IP filters and virtual network rules, the portal previously checked Selected Networks on the Networking page of your namespace. Now, it checks the All networks option.
:::image type="content" source="./media/event-hubs-firewall/firewall-all-networks-selected.png" lightbox="./media/event-hubs-firewall/firewall-all-networks-selected.png" alt-text="Screenshot that shows the Public access page with the All networks option selected.":::
To constrain access to Event Hubs to Azure virtual networks, see the following article: