Tutorial: Restrict network access to PaaS resources with virtual network service endpoints using the Azure portal
Virtual network service endpoints enable you to limit network access to some Azure service resources to a virtual network subnet. You can also remove internet access to the resources. Service endpoints provide direct connection from your virtual network to supported Azure services, allowing you to use your virtual network's private address space to access the Azure services. Traffic destined to Azure resources through service endpoints always stays on the Microsoft Azure backbone network. In this tutorial, you learn how to:
- Create a virtual network with one subnet
- Add a subnet and enable a service endpoint
- Create an Azure resource and allow network access to it from only a subnet
- Deploy a virtual machine (VM) to each subnet
- Confirm access to a resource from a subnet
- Confirm access is denied to a resource from a subnet and the internet
If you don't have an Azure subscription, create a free account before you begin.
Log in to Azure
Log in to the Azure portal at https://portal.azure.com.
Create a virtual network
Select + Create a resource on the upper, left corner of the Azure portal.
Select Networking, and then select Virtual networks.
Click + Add and enter the following information:
Setting Value Subscription Select your subscription Resource group Select Create new and enter myResourceGroup. Name Enter myVirtualNetwork Region Select (US) East US
Click Next: IP addresses >
Setting Value IPv4Address space Leave as default Subnet name Click default and change the name from "default" to "Public" Subnet Address Range Leave as default
Click Next: Security >
Setting Value BastionHost Disable DDoS protection Disable Firewall Disable
When complete, click Review and create.
If the validation checks pass, click Create.
Wait for the deployment to finish, then click Go to resource or move on to the next section.
Enable a service endpoint
Service endpoints are enabled per service, per subnet. To create a subnet and enable a service endpoint for the subnet:
If you are not already on the virtual network resource page, you can search for the newly created network in the Search resources, services, and docs box at the top of the portal, enter myVirtualNetwork, and select it from the list.
In the Settings menu (left), select Subnets, and then select + Subnet, as shown:
Under Add subnet, select or enter the following information, and then select OK:
Setting Value Name Private Address range Leave as default Service endpoints Select Microsoft.Storage Service endpoint policies Leave default as 0
Before enabling a service endpoint for an existing subnet that has resources in it, see Change subnet settings.
- Click Save, then close the Subnet window on the right. The newly created subnet should appear the list.
Restrict network access for a subnet
By default, all virtual machine instances in a subnet can communicate with all resources. You can limit communication to and from all resources in a subnet by creating a network security group, and associating it to the subnet:
Select All services in the upper left corner of the Azure portal.
Select Networking, and then select (or search for) Network security groups.
From the Network security groups page, click + Add.
Enter the following information
Setting Value Subscription Select your subscription Resource group Select myResourceGroup from the list Name Enter myNsgPrivate Location Select East US
Click Review + create, and when the validation check is passed, click Create.
After the network security group is created, click Go to resource or search for myNsgPrivate.
Under Settings on the left, select Outbound security rules.
Select + Add.
Create a rule that allows outbound communication to the Azure Storage service. Enter, or select, the following information, and then select Add:
Setting Value Source Select VirtualNetwork Source port ranges * Destination Select Service Tag Destination service tag Select Storage Destination port ranges Leave default as 8080 Protocol Any Action Allow Priority 100 Name Rename to Allow-Storage-All
Create another outbound security rule that denies communication to the internet. This rule overrides a default rule in all network security groups that allows outbound internet communication. Complete steps 6-9 from above using the following values:
Setting Value Source Select VirtualNetwork Source port ranges * Destination Select Service Tag Destination service tag Select Internet Destination port ranges * Protocol Any Action Change default to Deny Priority 110 Name Change to Deny-Internet-All
Create an inbound security rule that allows Remote Desktop Protocol (RDP) traffic to the subnet from anywhere. The rule overrides a default security rule that denies all inbound traffic from the internet. Remote desktop connections are allowed to the subnet so that connectivity can be tested in a later step.
Under Settings, select Inbound security rules.
Select + Add and use the following values:
Setting Value Source Any Source port ranges * Destination Select VirtualNetwork Destination port ranges Change to 3389 Protocol Any Action Allow Priority 120 Name Change to Allow-RDP-All
RDP port 3389 is exposed to the Internet. This is only recommended for testing. For Production environments, we recommend using a VPN or private connection.
- Under Settings, select Subnets.
- Click + Associate.
- Under Virtual network, select myVirtualNetwork.
- Under Subnet, select Private, and then select Ok.
Restrict network access to a resource
The steps required to restrict network access to resources created through Azure services, which are enabled for service endpoints will vary across services. See the documentation for individual services for specific steps for each service. The remainder of this tutorial includes steps to restrict network access for an Azure Storage account, as an example.
Create a storage account
Select + Create a resource on the upper, left corner of the Azure portal.
Enter "Storage account" in the search bar, and select it from the drop-down menu.
Click + Add.
Enter the following information:
Setting Value Subscription Select your subscription Resource group Select myResourceGroup Storage Account Name Enter a name that is unique across all Azure locations, between 3-24 characters in length, using only numbers and lower-case letters. Location Select (US) East US Performance Standard Account kind StorageV2 (general purpose v2) Replication Locally-redundant storage (LRS)
Select Create + review, and when validation checks have passed, click Create.
The deployment may take a couple of minutes to complete.
- After the storage account is created, click Go to resource
Create a file share in the storage account
Go to your storage account overview page.
Select the File Shares app icon, then click + File share.
Setting Value Name my-file-share Quota 'Set to maximum'
The file share should be shown in the Azure window, if not click Refresh
Restrict network access to a subnet
By default, storage accounts accept network connections from clients in any network, including the internet. You can restrict network access from the internet, and all other subnets in all virtual networks (except the Private subnet in the myVirtualNetwork virtual network.) To restrict network access to a subnet:
Under Settings for your (uniquely named) storage account, select Networking.
Select Selected networks.
Select + Add existing virtual network.
Under Add networks, select the following values, and then select Add:
Setting Value Subscription Select your subscription Virtual networks myVirtualNetwork Subnets Private
Click Add and, then immediately click the Save icon to save the changes.
Under Settings for the storage account, select Access keys, as shown in the following image:
Click Show keys and note the Key values, as you'll have to manually enter key1 in a later step when mapping the file share to a drive letter in a VM.
Create virtual machines
To test network access to a storage account, deploy a VM to each subnet.
Create the first virtual machine
From the "Search resources . . ." bar, search for Virtual machines.
Select + Add > Virtual machine.
Enter, the following information:
Setting Value Subscription Select your subscription Resource group Select **myResourceGroup, which was created earlier. Virtual machine name Enter myVmPublic Region (US) East US Availability options Availability zone Availability zone 1 Image Windows Server 2019 Datacenter - Gen1 Size Select the VM Instance size you want to use Username Enter a user name of your choosing. Password Enter a password of your choosing. The password must be at least 12 characters long and meet the defined complexity requirements. Public inbound ports Allow selected ports Select inbound ports Leave default set to RDP (3389)
Select the Networking tab and then select myVirtualNetwork.
Select the Public subnet.
Under NIC Network Security Group, select Advanced. The portal automatically creates a network security group for you that allows port 3389, which you'll need open to connect to the virtual machine in a later step.
Select Review and create, then Create and wait for the deployment to finish.
Click Go to resource, or open the Home > Virtual machines page, and select the VM you just created myVmPublic, which should be started.
Create the second virtual machine
- Complete steps 1-8 again, but in step 3, name the virtual machine myVmPrivate and set Public inbound port to "None".
- In step 4-5, select the Private subnet.
The NIC network security group and Public inbound ports settings should mirror the image shown below, including the blue confirmation window stating: "all public internet traffic will be blocked by default".
- Select Review and create, then Create and wait for the deployment to finish.
Please do not continue to the next step until the deployment is complete.
Wait for the confirmation window shown below and click Go to resource.
Confirm access to storage account
Once the myVmPrivate VM has been created, click Go to resource.
Connect to the VM by selecting the Connect > RDP.
After selecting the Connect button, a Remote Desktop Protocol (.rdp) file is created. Click Download RDP File to download to your computer.
Open the downloaded rdp file. If prompted, select Connect. Enter the user name and password you specified when creating the VM. You may need to select More choices, then Use a different account to specify the credentials you entered when you created the VM. For the email field, enter the "Administrator account: username" credentials you specified earlier.
You may receive a certificate warning during the sign-in process. If you receive the warning, select Yes or Continue, to proceed with the connection. You should see the VM start as shown:
In the VM window, open a PowerShell CLI instance.
Using the script below, map the Azure file share to drive Z using PowerShell. Before running the commands that follow, replace
<storage-account-name>fields with values you supplied and "d earlier in Create a storage account.
$acctKey = ConvertTo-SecureString -String "<storage-account-key>" -AsPlainText -Force $credential = New-Object System.Management.Automation.PSCredential -ArgumentList "Azure\<storage-account-name>", $acctKey New-PSDrive -Name Z -PSProvider FileSystem -Root "\\<storage-account-name>.file.core.windows.net\my-file-share" -Credential $credential
PowerShell returns output similar to the following example output:
Name Used (GB) Free (GB) Provider Root ---- --------- --------- -------- ---- Z FileSystem \\vnt.file.core.windows.net\my-f...
The Azure file share successfully mapped to the Z drive.
Close the remote desktop session to the myVmPrivate VM.
Confirm access is denied to storage account
Enter myVmPublic In the Search resources, services, and docs box at the top of the portal.
When myVmPublic appears in the search results, select it.
Complete steps 1-8 above in Confirm access to storage account for the myVmPublic VM.
After a short wait, you receive a
New-PSDrive : Access is deniederror. Access is denied because the myVmPublic VM is deployed in the Public subnet. The Public subnet does not have a service endpoint enabled for Azure Storage. The storage account only allows network access from the Private subnet, not the Public subnet.
Close the remote desktop session to the myVmPublic VM.
Back in the Azure portal, go to the uniquely named storage account you created earlier.
Under File Service, select File shares, the my-file-share, created earlier.
You should receive the following error message:
Access is denied, because your computer is not in the Private subnet of the MyVirtualNetwork virtual network.
Clean up resources
When no longer needed, delete the resource group and all resources it contains:
- Enter myResourceGroup in the Search box at the top of the portal. When you see myResourceGroup in the search results, select it.
- Select Delete resource group.
- Enter myResourceGroup for TYPE THE RESOURCE GROUP NAME: and select Delete.
In this tutorial, you enabled a service endpoint for a virtual network subnet. You learned that you can enable service endpoints for resources deployed from multiple Azure services. You created an Azure Storage account and restricted network access to the storage account to only resources within a virtual network subnet. To learn more about service endpoints, see Service endpoints overview and Manage subnets.
If you have multiple virtual networks in your account, you may want to connect two virtual networks together so the resources within each virtual network can communicate with each other. To learn how to connect virtual networks, advance to the next tutorial.