Azure Private Subnet Networking Design and Security

Azure private subnets provide a secure way to isolate resources, but designing a robust network requires careful planning. A private subnet can be created within a virtual network, and it's a good practice to use a separate subnet for each resource or application.

To ensure security, it's essential to use Network Security Groups (NSGs) to control inbound and outbound traffic. NSGs can be attached to subnets and can be used to allow or deny traffic based on source IP address, destination IP address, and protocol.

A private subnet can be used to protect sensitive data by isolating it from the public internet. This can be achieved by not assigning a public IP address to the subnet, and by using a private IP address range. This helps to prevent unauthorized access to the subnet and its resources.

A virtual network (VNet) is the fundamental building block where you can launch Azure resources. It is dedicated to your Azure account and serves as the networking layer of Azure VMs.

Azure VNet spans all the Availability Zones in the region, allowing you to add one or more subnets in each Availability Zone. This gives you flexibility and redundancy in your network architecture.

You can create a virtual network in the cloud and specify an IP address range for the VNet. This allows you to add subnets, associate network security groups, and configure route tables.

Here are some key features of a virtual network:

To protect the Azure resources in each subnet, use network security groups. This will help ensure that your resources are secure and compliant with your organization's security policies.

A virtual network, or VNet, is the fundamental building block of Azure resources.

You can create a virtual network in the cloud dedicated to your Azure account, which spans all the Availability Zones in the region. After creating a VNet, you can add one or more subnets in each Availability Zone.

A subnet is a range of IP addresses in your VNet, where you can launch Azure resources.

To protect the Azure resources in each subnet, use network security groups.

You can connect VNets to each other using VNet peering.

Here are some common VNet components:

A virtual network allows you to specify an IP address range for the VNet, add subnets, associate network security groups, and configure route tables.

To create or edit a VNet and subnet, you need to follow these steps:

Service Endpoint is an option where the Microsoft backbone manages routes to PaaS services.

This means that even if your workload doesn't have access to the Internet, you can still connect to the PaaS service.

The next hop is not the Internet, but the VirtualNetworkServiceEndpoint, which acts like the endpoint is part of the Virtual Network.

This allows you to connect to the PaaS service even if it still uses a Public IP.

The VirtualNetworkServiceEndpoint is a virtual network route that enables this connection.

Private Link is the solution if you want to keep the VM out of the Internet and use your Virtual Network private IPs.

Azure Private Link creates a vNIC in a subnet for the PaaS so your workload uses a private IP to connect to the service.

Service Endpoint and Private Link can be used with the private subnet feature to access Azure PaaS services.

Service endpoint is not available for all Azure services.

Private Link requires that you manage a private DNS zone for each service, which can be easy for a standalone subscription using Azure DNS.

For organizations with their own DNS resolvers, the configuration is much more complex.

To create a VNet, you must specify a range of IPv4 addresses in the form of a CIDR block, such as 10.0.0.0/16.

A CIDR block must not overlap with any existing CIDR block associated with your VNet. You can add multiple subnets in each Availability Zone of your VNet's region.

The CIDR block size of an IPv4 address is between a /16 netmask (65,536 IP addresses) and /29 netmask (8 IP addresses).

A subnet is a range of IP addresses in your VNet, and you can launch Azure resources into a specified subnet.

Here are the possible values for delegating a subnet to a service: Microsoft.Network/networkinterfaces/*Microsoft.Network/publicIPAddresses/join/actionMicrosoft.Network/publicIPAddresses/readMicrosoft.Network/virtualNetworks/readMicrosoft.Network/virtualNetworks/subnets/actionMicrosoft.Network/virtualNetworks/subnets/join/actionMicrosoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/actionMicrosoft.Network/virtualNetworks/subnets/unprepareNetworkPolicies/action

A virtual network, or VNet, is a fundamental concept in Azure. It allows you to specify an IP address range for the VNet, add subnets, associate network security groups, and configure route tables.

You can launch Azure resources into a specified subnet. This is where things get interesting - you have the option to create a public subnet for resources that need to connect to the Internet and a private subnet for resources that won't be connected to the Internet.

Subnets are essentially a range of IP addresses in your VNet. They're like separate little neighborhoods within your virtual network.

To protect the Azure resources in each subnet, use network security groups. These groups help filter traffic and ensure only authorized access to your resources.

Here are some key benefits of using network security groups:

By following these best practices, you can create a secure and well-organized virtual network in Azure.

Creating a subnet in Azure requires specifying a range of IPv4 addresses in the form of a CIDR block, such as 10.0.0.0/16. You must ensure that the CIDR block does not overlap with any existing block associated with your VNet.

A CIDR block's size can vary between a /16 netmask (65,536 IP addresses) and /29 netmask (8 IP addresses). This means you have a range of options to choose from depending on your needs.

You can add multiple subnets in each Availability Zone of your VNet's region. This is useful for organizing your resources and improving scalability.

There are 5 reserved addresses in each CIDR block that are not available for use and cannot be assigned to any virtual machines. These addresses are typically reserved for system use.

Here are the possible actions that can be delegated to a subnet:

Azure may add default actions depending on the service delegation name, and these cannot be changed.

Network Security Groups are a crucial component of Azure's security features, controlling the inbound and outbound traffic of Azure resources.

You can use service tags on network security rules to minimize the complexity of frequent updates.

Augmented security rules allow you to create a single rule with multiple source and destination IPs.

Application Security Groups enable you to define a VMs group network security policy.

IP flow verify of Azure Network Watcher can check which network security rule allows or denies the traffic.

With VNet service endpoint policy, you can filter the egress VNet traffic to Azure Storage.

Network Security Groups (NSGs) are a crucial part of Azure's security features, allowing you to control the inbound and outbound traffic of Azure resources.

To minimize the complexity of frequent updates, you can use service tags on network security rules.

Augmented security rules make it easy to create a single rule with multiple source and destination IPs.

Application Security Groups allow you to define a VMs group network security policy, giving you more control over your virtual machines.

You can use IP flow verify of Azure Network Watcher to check which network security rule allows or denies the traffic, helping you troubleshoot any issues.

With VNet service endpoint policy, you can filter the egress VNet traffic to Azure Storage, adding an extra layer of security to your data transfer.

Here are some key security features to keep in mind:

Creating an endpoint is a straightforward process that can greatly enhance your security setup.

Service Endpoint is an option where the Microsoft backbone manages routes to PaaS services.

To create an endpoint, you'll first need to understand the concept of a Virtual Network Service Endpoint.

This acts like the endpoint is part of the Virtual Network.

By doing so, you can connect to the PaaS service even if it still uses a Public IP and your workload don't have access to the Internet.

This is a key benefit of using Service Endpoint.