Azure Networking – Virtual Network (VNet)

Azure Virtual Network (VNet) is a fundamental building block of the Azure networking architecture that enables you to securely connect Azure resources to each other and to on-premises networks. In this article, we will take a closer look at Azure VNet, its components, and how to configure it.

Components of Azure VNet:

1. Subnets: A subnet is a range of IP addresses within a VNet that you can use to allocate resources, such as virtual machines, Azure Kubernetes Service (AKS) clusters, or Azure Functions. You can segment a VNet into multiple subnets to isolate workloads and control traffic flow.
2. Network Security Groups (NSGs): An NSG is a firewall-like security group that you can associate with subnets or network interfaces to control traffic flow to and from Azure resources. You can define inbound and outbound rules that allow or deny traffic based on source and destination IP address, protocol, and port.
3. Virtual Network Peering: VNet peering enables you to connect two VNets within the same Azure region or across different regions through a private and low-latency network. With VNet peering, you can exchange traffic between VNets as if they were on the same network, without the need for a VPN gateway.
4. Virtual Private Network (VPN) Gateway: A VPN gateway is a network device that enables you to establish secure and encrypted connections between on-premises networks and Azure VNets over the public internet. You can configure site-to-site or point-to-site VPN connections to extend your network to Azure.
5. Azure Private DNS: Azure Private DNS enables you to create a private DNS zone within a VNet that can resolve domain names to private IP addresses without exposing them to the public internet. You can use Private DNS to simplify the management of domain names for Azure resources and reduce DNS resolution latency.

Key Features of Azure Virtual Network

Azure Virtual Network provides a number of key features that make it a powerful networking tool for Azure resources:

1. Isolation: Azure Virtual Network provides a completely isolated network environment for Azure resources, ensuring that traffic within the Virtual Network is not visible or accessible from outside the Virtual Network.
2. Security: Azure Virtual Network provides a number of security features, including NSGs and Virtual Network Gateway, that allow administrators to control access to resources and secure traffic between Azure resources and on-premises networks.
3. Scalability: Azure Virtual Network is highly scalable, allowing administrators to add or remove resources from the Virtual Network as needed.
4. Availability: Azure Virtual Network is designed for high availability, with built-in redundancy and failover capabilities that ensure that the network is always available to Azure resources.

How to create an Azure VNet:

1. Navigate to the Azure Portal and select “Create a resource” from the left-hand menu.
2. Search for “Virtual Network” in the search bar and select “Virtual Network” from the results.
3. Fill out the required fields, such as the name and address space of the VNet, and select the Azure region where you want to deploy the VNet.
4. Configure the subnet(s) and NSG(s) for the VNet, and optionally enable VNet peering or VPN connectivity.
5. Review and validate the settings, then select “Create” to deploy the VNet.

Once the VNet is deployed, you can deploy Azure resources, such as virtual machines or AKS clusters, into the subnets of the VNet. You can also configure routing and network policies using NSGs, and establish secure connectivity between VNets and on-premises networks using VPN gateways or VNet peering.

Use case of Azure Virtual Network

Azure Virtual Network can be used in a variety of scenarios, including:

1. Hosting multi-tier applications: Azure Virtual Network can be used to host multi-tier applications, with each tier placed in a separate subnet with its own security rules and access controls.
2. Hybrid cloud: Azure Virtual Network can be used to connect Azure resources to on-premises networks, enabling hybrid cloud scenarios.
3. Disaster recovery: Azure Virtual Network can be used to replicate virtual machines and other resources to a secondary Azure region, providing disaster recovery capabilities.

Conclusion:

Azure Virtual Network is a powerful networking tool that provides a secure and isolated network environment for Azure resources. Its key features, including isolation, security, scalability, and availability, make it a valuable tool for hosting multi-tier applications, enabling hybrid cloud scenarios, and providing disaster recovery capabilities. By understanding the architecture and features of Azure Virtual Network, administrators can leverage its capabilities to build highly available and secure networking environments for their Azure resources.