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Harnessing the multicloud advantage: Comparing AWS and Azure network designs

Dileep-G

Microsoft

Apr 24, 2025

Expanding your Marketplace presence to Azure can help software development companies reach a wider customer base. With Azure’s global footprint and diverse cloud users, it offers a powerful platform for increased adoption. This article compares the networking services of AWS and Azure, highlighting their unique features and differences to aid in designing cloud-native solutions.

This post is part of a series on replicating apps from AWS to Azure. View all posts in this series.

To simplify your app replication, understanding how AWS and Azure approach networking—such as routing, connectivity, private access, and hybrid integration—can help you quickly align infrastructure components across clouds. This ensures consistent performance, security, and connectivity for your customers as you extend your offer to Azure.

You can also join ISV Success to get access to over $126K USD in cloud credits, AI services, developer tools, and 1:1 technical consults to help you replicate your app and publish to Azure Marketplace. To replicate your app faster get cloud-ready reference code to replicate AWS apps to Azure.

Software development companies looking to migrate or replicate their applications from AWS to Azure need to understand how networking services in both platforms compare. While AWS and Azure offer similar networking capabilities, key differences in architecture and service offerings can impact the overall solution design. This article provides a comparative overview of the networking services in AWS and Azure, focusing on their unique features and distinctions. By understanding these differences, software companies can make more informed decisions when architecting cloud-native solutions on either platform. The article explores networking services at a high level, with a deeper dive into critical areas such as peering, routing, and elastic load balancing, where the platforms diverge most significantly.

Networking services overview

Virtual networks & subnets

AWS uses Virtual Private Cloud (VPC) to create isolated networks, spanning all Availability Zones within a region. VPCs support public and private subnets, with VPC peering routing traffic between VPCs using private IPv4 or IPv6 addresses. Azure uses Virtual Networks (VNets), which provide isolation within a region and can span multiple Availability Zones. Azure's VNet peering connects multiple VNets, making them appear as one for connectivity purposes, routing traffic through Microsoft's private network. In AWS, subnets are confined to a specific AZ, while Azure subnets are not tied to a specific Availability Zone. This allows zonal resources to retain their private IPs even when placed in different zones within a region.

Peering

In AWS and Azure, transitive peering is not natively supported with standard VPC Peering connections. For example, VPC-A and VPC-C cannot communicate directly if they are only peered through VPC-B. To enable transitive routing, AWS offers Transit Gateway, which connects multiple VPCs, allowing traffic between VPC-A and VPC-C. Azure provides Azure Virtual WAN, a centralized hub-and-spoke architecture that simplifies global network connections with built-in transitive routing. VNet Peering uses static routing without BGP, while Azure Virtual WAN supports BGP for branch and ExpressRoute connectivity. Additionally, Azure Virtual WAN now supports BGP for inter-regional hub-to-hub routing, enabling dynamic route propagation across hubs, similar to AWS Transit Gateway peering across regions.

See Azure Virtual WAN Pricing for cost considerations.

Below is an example of Azure VNet Peering.

Traffic management services

AWS features Elastic Load Balancing (ELB) with Classic, Application, and Network Load Balancers. Azure has Azure Load Balancer, Azure Application Gateway, and Traffic Manager for load distribution and traffic management. Below is an application of Multi-region load balancing with Traffic Manager, Azure Firewall, and Application Gateway.

AWS provides a suite of load balancers including Application Load Balancer (ALB) for Layer 7 traffic, Network Load Balancer (NLB) for high-performance Layer 4 workloads, and Classic Load Balancer (CLB) as a legacy option. These services integrate with a broad set of AWS offerings such as EC2, ECS, and Lambda, and are complemented by Global Accelerator for improving global traffic performance. Azure’s approach to traffic management is more modular. Azure Load Balancer handles Layer 4 traffic and comes in Basic and Standard SKUs for varying scale and resiliency. For Layer 7 scenarios, Azure offers Application Gateway with features like SSL termination and integrated WAF. Azure Front Door adds global Layer 7 load balancing with content acceleration, while Azure Traffic Manager enables DNS-based routing with geo-failover. These services are often used in combination to build resilient architectures, rather than mirroring AWS's load balancer offerings one-to-one.

Content delivery and optimization

Both AWS and Azure provide robust content delivery network (CDN) services to accelerate the global delivery of content, applications, and APIs. AWS offers CloudFront, a globally distributed CDN service that integrates seamlessly with AWS services, enabling the fast delivery of web content, videos, and APIs to end users. On the Azure side, Azure Front Door acts as a modern, high-performance CDN that also includes advanced load balancing, security features, and seamless integration with Azure services. While both services focus on enhancing global content delivery, Azure Front Door goes a step further by offering enhanced scalability and secure user experiences for content-heavy applications and APIs.

Routing & gateways

AWS uses route tables associated with subnets in a VPC to direct traffic within and outside the network—for example, toward Internet Gateways, NAT Gateways, or VPN/Transit Gateways. Azure uses User-Defined Routes (UDRs), which can be applied to subnets in a Virtual Network (VNet) and managed centrally via Azure Network Manager.

The diagram shows a spoke network group of two VNets accessing a DNS service through a Firewall, where UDRs created by Network Manager make this routing possible.

AWS relies on explicit route configurations and services like Transit Gateway for transitive routing across VPCs. Azure creates system routes by default and allows UDRs to customize traffic flow to resources like VPN Gateways, NAT Gateways, or Network Virtual Appliances (NVAs). For internet egress, Azure currently allows implicit SNAT via Standard Public IPs or Load Balancers without outbound rules, but this behavior will be retired on September 30, 2025. After that, outbound access will require explicit configuration using a NAT Gateway, Load Balancer outbound rule, or Azure Firewall.

Both platforms provide VPN solutions for hybrid connectivity. AWS supports Site-to-Site VPN for linking on-premises data centers with VPCs, and Client VPN for individual users. Azure offers Site-to-Site (S2S) and Point-to-Site (P2S) VPNs, as well as VNet-to-VNet connections for secure inter-region communication. These VPN services work with their respective routing infrastructures to support secure hybrid and multi-region deployments.

DNS services

DNS plays a foundational role in service discovery and network communication across both AWS and Azure environments. AWS offers Route 53, a scalable DNS service that supports both public and private hosted zones. It provides features like health checks, weighted routing, and integration with AWS services for domain resolution. Azure delivers similar functionality through Azure DNS for public DNS hosting and Azure Private DNS for internal name resolution within VNets. Azure Private DNS zones can be linked to one or more VNets, enabling seamless name resolution without custom DNS servers. These services are often used alongside load balancers and private endpoints to ensure consistent, secure access to application components.

Private connectivity

Both AWS and Azure offer dedicated, high-performance private connections to enhance security and reduce latency for hybrid and multi-cloud architectures. AWS provides Direct Connect, which establishes a dedicated network connection from an on-premises data center to AWS. This ensures a more consistent network experience, particularly for workloads requiring low latency or high throughput. Similarly, Azure offers ExpressRoute, a private, dedicated connection from on-premises infrastructure to Azure, bypassing the public internet. These private links typically use technologies like MPLS or Ethernet, depending on the provider and partner, offering better performance and reliability than traditional VPNs. ExpressRoute connections are often used for mission-critical workloads, offering greater reliability, faster speeds, and enhanced security.

Security groups and network ACLs

Network-level security

AWS offers Security Groups (stateful) and Network ACLs (stateless) for network-level security. Security Groups are applied at the instance level, while NACLs work at the subnet boundary, adding an extra layer of filtering. Azure uses Network Security Groups (NSGs) and Application Security Groups (ASGs), which are fully stateful and simplify rule management. NSGs can be applied at both the subnet and network interface level. While Azure lacks a direct equivalent to stateless NACLs, NSGs typically offer enough granularity for most use cases.

Azure also offers more granular traffic control with User-Defined Routes (UDRs) and the option to disable "Allow forwarded traffic" in virtual network peering settings. This ensures tight control or blocking of traffic even between peered VNets.

Web Application Firewall (WAF)

When it comes to Web Application Firewalls, AWS and Azure differ in design and deployment models. AWS WAF can be deployed as a standalone resource and attached to services like CloudFront, API Gateway, or the Application Load Balancer. This offers a high degree of flexibility but may require more hands-on setup and configuration. In contrast, Azure WAF is designed to work in close integration with services such as Application Gateway and Azure Front Door. While not standalone, central WAF policies allow consistent policy reuse across deployments.

From a performance perspective, AWS WAF is recognized for its robust application-layer controls and ability to handle high traffic loads efficiently. Azure WAF is often noted for its ease of setup and the depth of its reporting and diagnostics.

Private access to PaaS services and Private Endpoints

As cloud-native applications increasingly depend on managed services like storage, databases, and messaging queues, securely connecting to these services without exposing traffic to the public internet becomes a critical design consideration. In AWS, VPC Endpoints—available as Interface or Gateway types—allow private connectivity to supported services from within a VPC. Azure provides a similar capability through Private Link, leveraging Private endpoints enabling private access to Azure services such as Azure Storage, SQL Database, or even custom services behind a Load Balancer. Azure Private Link also supports private access to customer or partner services published via Azure Private Link Service. Both approaches improve security posture by keeping traffic on the cloud provider's internal backbone, reducing exposure to external threats. For software development companies building multi-tiered cloud-native applications, these features offer a straightforward way to lock down service-to-service communication without relying on public endpoints.

Endpoint policy management

In AWS, endpoint management is handled via VPC Endpoint Policies, API Gateway, and AWS PrivateLink. These resource-specific policies are applied to services like S3, DynamoDB, or API Gateway, offering granular control, but requiring more configuration. In contrast, Azure’s endpoint management is more centralized. Services like Azure Application Gateway, Front Door, and Private Endpoint are governed through Network Security Groups (NSGs), Azure Firewall, and WAF policies. Azure's centralized policy enforcement, particularly for Private Endpoints, provides simplified access control and reduces the need for per-service configurations. AWS offers granular control at the cost of additional configuration complexity.

Service mesh for Microservices

For applications composed of many microservices, managing east-west traffic, enforcing security policies, and gaining observability into service communication can become complex. A service mesh addresses these challenges by abstracting service-to-service communication into a dedicated infrastructure layer. AWS offers App Mesh, which integrates with ECS, EKS, and Fargate, providing features like traffic shifting, retries, circuit breaking, and mTLS encryption. Azure supports service meshes primarily through open-source solutions like Istio and Linkerd, facilitated by managed integrations via the AKs service mesh add-on, simplifying operations on AKS. Additionally, Azure provides Dapr, which complements service mesh by offering higher-level application concerns such as state management, pub/sub messaging and simplified service invocation. For cloud-native software development companies adopting Kubernetes or containerized architectures, a service mesh brings consistency, security, and fine-grained control to internal traffic management.

Monitoring and observability

Azure Network Watcher provides tools for monitoring, diagnosing, and logging network performance across IaaS resources in Azure. Key features include topology visualization, connection monitoring, and various diagnostic tools like IP flow verification, NSG diagnostics, and packet capture. Additionally, Traffic Analytics provides insights into network traffic patterns. These tools support both hybrid and fully cloud-based network infrastructures, enabling efficient troubleshooting and performance optimization. On the AWS side, VPC Flow Logs and Reachability Analyzer provide comparable visibility and connectivity diagnostics.

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