Azure networking services overview

The networking services in Azure provide a variety of networking capabilities that can be used together or separately. Select any of the following key capabilities to learn more about them:

• Connectivity services: Connect Azure resources and on-premises resources using any or a combination of these networking services in Azure - Virtual Network (VNet), Virtual WAN, ExpressRoute, VPN Gateway, Virtual network NAT Gateway, Azure DNS, Peering service, Route Server, and Azure Bastion.
• Application protection services: Protect your applications using any or a combination of these networking services in Azure - Load Balancer, Private Link, DDoS protection, Firewall, Network Security Groups, Web Application Firewall, and Virtual Network Endpoints.
• Application delivery services: Deliver applications in the Azure network using any or a combination of these networking services in Azure - Content Delivery Network (CDN), Azure Front Door Service, Traffic Manager, Application Gateway, Internet Analyzer, and Load Balancer.
• Network monitoring: Monitor your network resources using any or a combination of these networking services in Azure - Network Watcher, ExpressRoute Monitor, Azure Monitor, or VNet Terminal Access Point (TAP).

Connectivity services

This section describes services that provide connectivity between Azure resources, connectivity from an on-premises network to Azure resources, and branch to branch connectivity in Azure - Virtual Network (VNet), ExpressRoute, VPN Gateway, Virtual WAN, Virtual network NAT Gateway, Azure DNS, Peering service, Route Server, and Azure Bastion.

Virtual network

Azure Virtual Network (VNet) is the fundamental building block for your private network in Azure. You can use VNets to:

• Communicate between Azure resources: You can deploy virtual machines, and several other types of Azure resources to a virtual network, such as Azure App Service Environments, the Azure Kubernetes Service (AKS), and Azure Virtual Machine Scale Sets. To view a complete list of Azure resources that you can deploy into a virtual network, see Virtual network service integration.
• Communicate between each other: You can connect virtual networks to each other, enabling resources in either virtual network to communicate with each other, using virtual network peering. The virtual networks you connect can be in the same, or different, Azure regions. For more information, see Virtual network peering.
• Communicate to the internet: All resources in a VNet can communicate outbound to the internet, by default. You can communicate inbound to a resource by assigning a public IP address or a public Load Balancer. You can also use Public IP addresses or public Load Balancer to manage your outbound connections.
• Communicate with on-premises networks: You can connect your on-premises computers and networks to a virtual network using VPN Gateway or ExpressRoute.

For more information, see What is Azure Virtual Network?

ExpressRoute

ExpressRoute enables you to extend your on-premises networks into the Microsoft cloud over a private connection facilitated by a connectivity provider. This connection is private. Traffic doesn't go over the internet. With ExpressRoute, you can establish connections to Microsoft cloud services, such as Microsoft Azure, Microsoft 365, and Dynamics 365. For more information, see What is ExpressRoute?

VPN Gateway

VPN Gateway helps you create encrypted cross-premises connections to your virtual network from on-premises locations, or create encrypted connections between VNets. There are different configurations available for VPN Gateway connections. Some of the main features include:

• Site-to-site VPN connectivity
• Point-to-site VPN connectivity
• VNet-to-VNet VPN connectivity

The following diagram illustrates multiple site-to-site VPN connections to the same virtual network. To view more connection diagrams, see VPN Gateway - design. For more information about VPN Gateway, see What is VPN Gateway?

Virtual WAN

Azure Virtual WAN is a networking service that brings many networking, security, and routing functionalities together to provide a single operational interface. Connectivity to Azure VNets is established by using virtual network connections. Some of the main features include:

• Branch connectivity (via connectivity automation from Virtual WAN Partner devices such as SD-WAN or VPN CPE)
• Site-to-site VPN connectivity
• Remote user VPN connectivity (point-to-site)
• Private connectivity (ExpressRoute)
• Intra-cloud connectivity (transitive connectivity for virtual networks)
• VPN ExpressRoute inter-connectivity
• Routing, Azure Firewall, and encryption for private connectivity

For more information, see What is Azure Virtual WAN?

Azure DNS

Azure DNS is a hosting service for DNS domains that provides name resolution by using Microsoft Azure infrastructure. By hosting your domains in Azure, you can manage your DNS records by using the same credentials, APIs, tools, and billing as your other Azure services. For more information, see What is Azure DNS?

Azure Bastion

Azure Bastion is a service that you can deploy to let you connect to a virtual machine using your browser and the Azure portal, or via the native SSH or RDP client already installed on your local computer. The Azure Bastion service is a fully platform-managed PaaS service that you provision inside your virtual network. It provides secure and seamless RDP/SSH connectivity to your virtual machines directly from the Azure portal over TLS. When you connect via Azure Bastion, your virtual machines don't need a public IP address, agent, or special client software. For more information, see What is Azure Bastion?

Virtual network NAT Gateway

Virtual Network NAT (network address translation) simplifies outbound-only Internet connectivity for virtual networks. When configured on a subnet, all outbound connectivity uses your specified static public IP addresses. Outbound connectivity is possible without load balancer or public IP addresses directly attached to virtual machines. For more information, see What is virtual network NAT gateway?

Route Server

Azure Route Server simplifies dynamic routing between your network virtual appliance (NVA) and your virtual network. It allows you to exchange routing information directly through Border Gateway Protocol (BGP) routing protocol between any NVA that supports the BGP routing protocol and the Azure Software Defined Network (SDN) in the Azure Virtual Network (VNet) without the need to manually configure or maintain route tables. For more information, see What is Azure Route Server?

Peering Service

Azure Peering service enhances customer connectivity to Microsoft cloud services such as Microsoft 365, Dynamics 365, software as a service (SaaS) services, Azure, or any Microsoft services accessible via the public internet. For more information, see What is Azure Peering Service?

Application protection services

This section describes networking services in Azure that help protect your network resources - Protect your applications using any or a combination of these networking services in Azure - DDoS protection, Private Link, Firewall, Web Application Firewall, Network Security Groups, and Virtual Network Service Endpoints.

DDoS Protection

Azure DDoS Protection provides countermeasures against the most sophisticated DDoS threats. The service provides enhanced DDoS mitigation capabilities for your application and resources deployed in your virtual networks. Additionally, customers using Azure DDoS Protection have access to DDoS Rapid Response support to engage DDoS experts during an active attack.

Azure Private Link

Azure Private Link enables you to access Azure PaaS Services (for example, Azure Storage and SQL Database) and Azure hosted customer-owned/partner services over a private endpoint in your virtual network. Traffic between your virtual network and the service travels through the Microsoft backbone network. Exposing your service to the public internet is no longer necessary. You can create your own private link service in your virtual network and deliver it to your customers.

Azure Firewall

Azure Firewall is a managed, cloud-based network security service that protects your Azure Virtual Network resources. Using Azure Firewall, you can centrally create, enforce, and log application and network connectivity policies across subscriptions and virtual networks. Azure Firewall uses a static public IP address for your virtual network resources allowing outside firewalls to identify traffic originating from your virtual network.

For more information about Azure Firewall, see the Azure Firewall documentation.

Web Application Firewall

Azure Web Application Firewall (WAF) provides protection to your web applications from common web exploits and vulnerabilities such as SQL injection, and cross site scripting. Azure WAF provides out of box protection from OWASP top 10 vulnerabilities via managed rules. Additionally customers can also configure custom rules, which are customer managed rules to provide additional protection based on source IP range, and request attributes such as headers, cookies, form data fields or query string parameters.

Customers can choose to deploy Azure WAF with Application Gateway which provides regional protection to entities in public and private address space. Customers can also choose to deploy Azure WAF with Front Door which provides protection at the network edge to public endpoints.

Network security groups

You can filter network traffic to and from Azure resources in an Azure virtual network with a network security group. For more information, see Network security groups.

Service endpoints

Virtual Network (VNet) service endpoints extend your virtual network private address space and the identity of your VNet to the Azure services, over a direct connection. Endpoints allow you to secure your critical Azure service resources to only your virtual networks. Traffic from your VNet to the Azure service always remains on the Microsoft Azure backbone network. For more information, see Virtual network service endpoints.

Application delivery services

This section describes networking services in Azure that help deliver applications - Content Delivery Network, Azure Front Door Service, Traffic Manager, Load Balancer, and Application Gateway.

Azure Front Door

Azure Front Door enables you to define, manage, and monitor the global routing for your web traffic by optimizing for best performance and instant global failover for high availability. With Front Door, you can transform your global (multi-region) consumer and enterprise applications into robust, high-performance personalized modern applications, APIs, and content that reach a global audience with Azure. For more information, see Azure Front Door.

Traffic Manager

Azure Traffic Manager is a DNS-based traffic load balancer that enables you to distribute traffic optimally to services across global Azure regions, while providing high availability and responsiveness. Traffic Manager provides a range of traffic-routing methods to distribute traffic such as priority, weighted, performance, geographic, multi-value, or subnet. For more information about traffic routing methods, see Traffic Manager routing methods.

The following diagram shows endpoint priority-based routing with Traffic Manager:

For more information about Traffic Manager, see What is Azure Traffic Manager?

Load Balancer

The Azure Load Balancer provides high-performance, low-latency Layer 4 load-balancing for all UDP and TCP protocols. It manages inbound and outbound connections. You can configure public and internal load-balanced endpoints. You can define rules to map inbound connections to back-end pool destinations by using TCP and HTTP health-probing options to manage service availability. To learn more about Load Balancer, read the Load Balancer overview article.

Azure Load Balancer is available in Standard, Regional, and Gateway SKUs.

The following picture shows an Internet-facing multi-tier application that utilizes both external and internal load balancers:

Application Gateway

Azure Application Gateway is a web traffic load balancer that enables you to manage traffic to your web applications. It's an Application Delivery Controller (ADC) as a service, offering various layer 7 load-balancing capabilities for your applications. For more information, see What is Azure Application Gateway?

The following diagram shows url path-based routing with Application Gateway.

Content Delivery Network

Azure Content Delivery Network (CDN) offers developers a global solution for rapidly delivering high-bandwidth content to users by caching their content at strategically placed physical nodes across the world. For more information about Azure CDN, see Azure Content Delivery Network.

Network monitoring services

This section describes networking services in Azure that help monitor your network resources - Azure Network Watcher, Azure Monitor Network Insights, Azure Monitor, and ExpressRoute Monitor.

Azure Network Watcher

Azure Network Watcher provides tools to monitor, diagnose, view metrics, and enable or disable logs for resources in an Azure virtual network. For more information, see What is Network Watcher?

Azure Monitor

Azure Monitor maximizes the availability and performance of your applications by delivering a comprehensive solution for collecting, analyzing, and acting on telemetry from your cloud and on-premises environments. It helps you understand how your applications are performing and proactively identifies issues affecting them and the resources they depend on. For more information, see Azure Monitor Overview.

ExpressRoute Monitor

To learn about how to view ExpressRoute circuit metrics, resource logs and alerts, see ExpressRoute monitoring, metrics, and alerts.

Network Insights

Azure Monitor for Networks (Network Insights) provides a comprehensive view of health and metrics for all deployed network resources, without requiring any configuration. For more information, see Network Insights.

Next steps

• Create your first virtual network, and connect a few virtual machines to it, by completing the steps in the Create your first virtual network article.
• Connect your computer to a virtual network by completing the steps in the Configure a point-to-site connection article.
• Load balance Internet traffic to public servers by completing the steps in the Create an Internet-facing load balancer article.