Azure Virtual Machines Network Configuration Optimization Guide

Key Points

• Using accelerated networking is key for the best Azure VM performance. It provides up to 30Gbps throughput and reduces latency by bypassing the virtual switch.
• The size of your VM will directly impact the available network bandwidth. Larger compute-optimized and memory-optimized instances typically provide better network performance.
• Windows and Linux VMs need different optimization techniques. Linux offers more granular kernel-level network stack tuning options.
• If you configure your MTU settings correctly, you can significantly improve throughput for data-intensive workloads. This is especially true within the same virtual network.
• NetOps by Perimeter 81 offers comprehensive network monitoring and optimization tools. These can help you identify bottlenecks in your Azure VM network configuration.

Getting the Most Out of Your Azure VM: Essential Network Optimization

Network performance can make or break the experience of your cloud application. If your Azure Virtual Machines have throughput issues, latency problems, or connection limitations, even the most powerful compute resources won’t deliver the experience your users expect. Optimizing your Azure VM network configuration isn’t just a technical exercise. It’s a business imperative that directly impacts application responsiveness, user satisfaction, and operational costs.

While Azure VMs come with default network settings that offer basic functionality, they are often not the best choice for production workloads. With the right network optimization techniques, you can achieve up to 25-30Gbps throughput on supported VM sizes, a significant increase over unoptimized configurations. This guide will show you how to get the most out of your Azure VM network performance, going beyond the basic setup to make sure your cloud infrastructure is running as efficiently as possible.

The Importance of Network Optimization for Azure VMs

Network performance is a critical component of VM operations. Applications with high transaction volumes, data processing pipelines, database workloads, and web services all rely on dependable, high-speed network connectivity. If you don’t optimize your network properly, you’ll probably experience throughput bottlenecks, increased latency, and inconsistent application performance, even if you’ve provisioned powerful VM instances with plenty of CPU and memory resources.

There are several layers between your VM and the physical network hardware in Azure’s virtualized infrastructure. Each of these layers—from the virtual NIC to the hypervisor’s virtual switch to the physical network fabric—offers optimization opportunities. If you address these systematically, you can improve throughput by 30-40% or more, depending on your workload characteristics and VM configuration. Additionally, optimized network settings can reduce CPU overhead related to packet processing, freeing resources for your applications.

Usual Network Obstructions That Decelerate Your Cloud Infrastructure

There are several factors that typically lead to less than ideal Azure VM network performance. The most critical obstruction often lies in the virtual switch that processes network traffic in standard configurations. This software-defined component adds extra processing overhead for each packet, creating a performance penalty that is particularly noticeable in high-throughput scenarios. Many organizations neglect to enable accelerated networking, which completely bypasses this virtual switch.

Choosing the right VM size is crucial for network performance because Azure assigns specific bandwidth limits based on the type and size of the instance. If the workload requirements and VM capabilities don’t match, you may experience unexpected throttling. Moreover, the default TCP/IP stack configurations in both Windows and Linux operating systems are designed for general-purpose scenarios, not for the unique characteristics of cloud networking environments. If the TCP window sizes, buffer limits, and connection parameters are not optimal, the achievable throughput can be significantly reduced. For strategies on virtualized infrastructure, consider exploring additional resources.

Other frequent problems include inefficient communication patterns in applications, incorrect MTU (Maximum Transmission Unit) settings, and network security configurations that result in unnecessary packet inspection overhead. Each of these elements contributes to the creation of performance gaps that most organizations consider to be normal. However, these gaps actually represent significant opportunities for optimization.

Boosting VM Performance with Accelerated Networking

Accelerated Networking is the most important optimization for Azure VM network performance. It changes the way network traffic reaches your virtual machine by bypassing the software virtual switch in the hypervisor. Instead, it uses SR-IOV (Single Root I/O Virtualization) to allow the VM and the physical network adapter to communicate directly. This significantly reduces latency and increases throughput while also reducing CPU utilization.

When Accelerated Networking is not in use, all traffic going to and from your VM has to pass through a virtual switch in the host environment, which creates a bottleneck in processing. The default setup introduces additional latency of up to 500 microseconds for every packet. This overhead can add up to significant performance degradation for workloads with high packet rates or that are sensitive to latency. By using Accelerated Networking, you can reduce latency by up to 60% and at the same time increase maximum throughput.

How SR-IOV Technology Enables Accelerated Networking

SR-IOV technology is the basis of Accelerated Networking. It creates a direct datapath between the network hardware and the VM. SR-IOV makes a single physical network adapter (PCI Express device) seem like multiple virtual devices that can be assigned directly to VMs. By doing this, the VM’s network traffic can avoid the hypervisor’s software switch processing completely. This removes a significant source of overhead and contention.

When turned on, the Azure host makes a virtual function (VF) for the VM using the physical network adapter and changes the datapath to allow direct communication. This setup gets rid of the traditional hypervisor switching layer from the packet processing path for most types of traffic. The outcome is much lower latency, higher packet rates, and less jitter, giving you more consistent and predictable network performance.

Accelerated Networking and VM Size

Accelerated Networking isn’t supported by all Azure VM sizes, so it’s important to choose the right VM series for the best network performance. In general, you can use Accelerated Networking with most general-purpose and compute-optimized VM series that have 2 or more vCPUs. However, the specific requirements can vary depending on the VM family. Accelerated Networking is supported on popular series like Dv2/DSv2, Dv3/DSv3, Ev3/ESv3, Fsv2, and most of the newer VM families.

Support for Accelerated Networking in VM Series

The following Azure VMs are supported:
Standard_D2s_v3 and larger
Standard_E2s_v3 and larger
Standard_F2s_v2 and larger
Standard_D2_v2 and larger
However, Standard_B-series is not supported, and Standard_A-series only has limited support (A8-A11 only).

How to Enable Accelerated Networking Through Portal, CLI, and PowerShell

There are several ways to enable Accelerated Networking, depending on your preferred management style. If you’re using the Azure Portal, you can turn on this feature when you’re setting up a new VM. Just go to the Networking tab and choose “Advanced” network settings. If you want to enable this feature on a VM that’s already up and running, you’ll need to deallocate the VM first. This will cause some downtime, which is something to keep in mind if you’re working in a production environment.

Teams that focus on automation will find that Azure CLI offers a simple method with the az network nic update command. You just need to set the --accelerated-networking parameter to true. If you’re a PowerShell user, you can use the Set-AzNetworkInterface cmdlet with similar parameters. Both methods allow for scripted deployment and configuration management. This makes them perfect for infrastructure-as-code implementations and for consistent configuration across large environments.

Checking That Your Acceleration Is Functioning Correctly

Once you’ve turned on Accelerated Networking, it’s important to make sure it’s working properly. If you’re using a Windows VM, you can look in the Device Manager to see if the Mellanox VF NIC or another network adapter with SR-IOV capability is there. You should see something like “Mellanox ConnectX-3 Virtual Function Ethernet Adapter”. If you’re using a Linux VM, you can run lspci to see the virtual function network device, and ethtool -S [interface] will show you offload statistics that tell you if SR-IOV is working.

Tools like iPerf3 that measure performance can give you a clear picture of how much better your throughput has become. You should see a big difference in both throughput and latency measurements when you compare them before and after you turn on Accelerated Networking. This is especially true for workloads that require a lot of bandwidth and are sensitive to latency. If you don’t see the performance improvements you’re expecting, make sure your VM size supports the feature and that there aren’t any network security configurations that are slowing things down.

Optimization Techniques Specific to Windows VM

Windows Server operating systems that are run on Azure VMs can take advantage of specific optimization techniques that are not applicable to Linux environments. While Microsoft has optimized Windows Server for cloud environments, there are several adjustments that can be made to further improve network performance. These Windows-specific optimizations are centered around TCP parameters, RSS (Receive Side Scaling) configurations, and network adapter settings, which can greatly enhance throughput for high-volume workloads.

How to Enable and Set Up Receive Side Scaling (RSS)

Receive Side Scaling, or RSS, is a vital technology for network adapters that allows network processing to be spread across multiple CPU cores, stopping one core from becoming a bottleneck. Although it’s usually enabled by default on most Azure Windows VM images, setting it up correctly can greatly improve performance. You can check the status of RSS using PowerShell with the command Get-NetAdapterRSS and you can optimize the setup with Set-NetAdapterRSS, where you can change things like the number of RSS queues and processor allocation.

For the best performance, set up RSS to use a number of queues that matches the number of vCPUs your VM can access, but don’t exceed the maximum your adapter can support. If your VM has more than 64 logical processors, make sure you’ve set up processor groups correctly. This will let you use the NUMA awareness feature in Windows Server. This setup helps distribute the load of network processing evenly across all available computational resources.

Optimizing TCP Parameters for Windows Virtual Machines

By adjusting Windows TCP settings, you can greatly enhance performance in cloud settings. Important optimizations involve expanding the TCP window size to account for Azure networks’ greater bandwidth-delay products, tweaking the TCP autotuning level, and altering initial congestion window settings. These changes enable Windows to make better use of the network bandwidth available, particularly for connections over long distances or workloads with high throughput.

By modifying the registry, you can make these changes permanent. The most important keys are HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\GlobalMaxTcpWindowSize and HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpWindowSize. For most Azure workloads, setting these values between 8MB and 16MB will give you the best results. However, depending on your application’s communication patterns and the VM’s available bandwidth, you may need to adjust these values. For more insights on optimizing virtual machines, explore virtualized infrastructure strategies.

Boosting Performance with Advanced Network Adapter Settings

Windows network adapters offer a plethora of advanced settings that can be optimized for Azure environments. Key parameters include Receive/Send Buffer sizes, Interrupt Moderation, and TCP Offload settings. These configurations can be modified through the Advanced tab for the network adapter in Device Manager or via PowerShell using the Set-NetAdapterAdvancedProperty cmdlet.

If you’re working with high-throughput workloads, you can avoid packet drops during traffic surges by increasing buffer sizes. Correctly configured interrupt moderation can also help maintain a balance between latency and CPU usage. Enabling TCP Offloading features such as Large Send Offload (LSO) and Checksum Offloading can take advantage of hardware acceleration capabilities and reduce CPU overhead. But if you notice any stability issues, it’s best to disable these features. Some virtualized environments may not be compatible with certain offload technologies.

Optimizing Network Performance for Linux VMs

Linux virtual machines offer a wide range of tuning capabilities for the network stack that can significantly boost performance when correctly set up. The Linux kernel provides detailed control over TCP/IP behavior, buffer sizes, and network queuing disciplines. To fully utilize these capabilities, it is necessary to understand both the approaches specific to each distribution and the general principles of network optimization in Linux.

Optimizing for Specific Distributions (Ubuntu, Red Hat, SUSE)

Each of the major Linux distributions has a slightly different way of handling network configuration. Ubuntu systems usually use Netplan for network configuration. Red Hat-based systems (RHEL, CentOS) use NetworkManager or traditional interface configurations. SUSE Linux Enterprise Server uses YAST or Wicked for network management. It’s important to understand these distribution-specific tools to make persistent optimization changes.

When dealing with Ubuntu VMs, you need to modify the configuration files found in /etc/netplan and then use netplan apply to implement the changes. For Red Hat systems, the network configurations are located in /etc/sysconfig/network-scripts/, while SUSE keeps them in /etc/sysconfig/network/. Even though these systems have different ways of storing configurations, most of the settings related to performance are done through sysctl parameters. These parameters function the same way across all distributions, which makes it easier to standardize the tuning process.

Tweaking Kernel Parameters for Better Network Throughput

The Linux kernel parameters offer a great deal of control over network performance. The parameters you’ll want to tweak are tcp_rmem and tcp_wmem (which control the TCP receive and send buffer sizes), tcp_mem (which controls system-wide TCP memory allocation), and net.core.rmem_max/wmem_max (which control the maximum receive/send socket buffer sizes). If your Azure VMs have high-bandwidth connections, you’ll need to increase these values significantly from their defaults in order to make full use of the available network capacity.

To make these adjustments, you’ll need to generate a configuration file in /etc/sysctl.d/. This file should include settings like net.ipv4.tcp_rmem = 4096 87380 16777216 and net.ipv4.tcp_wmem = 4096 65536 16777216. To apply these changes, use sysctl -p. These values will raise the maximum TCP window sizes, which will help to handle higher bandwidth-delay products in Azure networks. This will also help to avoid any throughput limitations that may occur due to default conservative settings.

Suggested Linux Kernel Parameters for Azure Virtual Machines

net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
net.ipv4.tcp_max_syn_backlog = 16348
net.core.netdev_max_backlog = 30000
net.ipv4.tcp_slow_start_after_idle = 0
net.ipv4.tcp_tw_reuse = 1

Optimizing Linux TCP/IP Stack

Aside from kernel parameters, Linux also has a robust set of command-line tools for tuning the network stack dynamically. The ‘ip’ command suite provides a wide range of control over interfaces, routing, and queuing disciplines. To achieve the highest throughput, you may want to adjust the TCP congestion control algorithms with the ‘sysctl net.ipv4.tcp_congestion_control’ command. In Azure environments, the ‘bbr’ algorithm usually performs better than the default ‘cubic’ for connections with high bandwidth and high latency. For more detailed guidance, you can refer to TCP/IP performance tuning in Azure.

You can use the ‘ethtool’ utility to make optimizations that are specific to the interface. If you use commands such as ‘ethtool -K eth0 tso on’, you can enable TCP Segmentation Offload, which can reduce CPU overhead for large data transfers. Likewise, ‘ethtool -G eth0 rx 4096 tx 4096’ can increase ring buffer sizes, which can reduce the chance of packet drops during traffic spikes. These adjustments can be especially helpful for workloads that require a lot of data, such as database replication or large file transfers between Azure VMs.

Improving Network Driver Performance

Linux network drivers have optimization options that can greatly boost performance. If you have Accelerated Networking enabled on your Azure VMs, the Mellanox driver offers features like adaptive interrupt moderation and advanced queue management. You can optimize interrupt handling behavior for specific workload patterns by adjusting these parameters through the modprobe configuration files in /etc/modprobe.d/.

To ensure that interruptions are distributed evenly across CPU cores, you’ll need to configure IRQ affinity. This will ensure that the network processing load is evenly distributed. You can do this by modifying /proc/irq/*/smp_affinity files or by using the ‘irqbalance’ service with a custom configuration. If your application processes a large number of network packets and requires high throughput, properly tuning IRQ handling is especially important. For more advanced configurations, you might consider exploring virtualized infrastructure solutions.

High-Performance Workloads Advanced Network Configuration

Applications that require high performance need a network configuration that is more specialized than basic optimizations. These advanced techniques use Azure-specific features and an understanding of network architecture to maximize throughput, minimize latency, and ensure predictable performance. Optimal performance for demanding workloads is achieved through strategic VM placement, bandwidth allocation, and network topology design.

For businesses that use applications that are sensitive to delays or services that handle a lot of data, these advanced methods should be included in a complete optimization plan. Although they require more planning and setup than basic optimizations, they often result in significant performance enhancements that directly benefit the business. These methods are especially useful for applications where network performance directly affects the user experience or the efficiency of operations.

Using Proximity Placement Groups to Reduce Latency

Proximity Placement Groups (PPGs) are a tool that can be used to decrease network latency between Azure VMs. They work by making sure the VMs are physically close to each other within an Azure datacenter. This reduces the time it takes for data to travel across the network. This is especially useful for applications that require a lot of communication between VMs or that are sensitive to changes in latency. For applications that use clustering, database mirroring, or microservices architectures, PPGs can cut network latency by 50% or more compared to when VMs are placed randomly.

For optimal use of Proximity Placement Groups (PPGs), make sure to create the group before setting up your virtual machines (VMs). Also, ensure that all VMs that need to communicate with each other are within the same group. However, keep in mind that using PPGs might lower VM availability during allocation or resizing since they limit placement to specific physical infrastructures. You should weigh this tradeoff against your application’s sensitivity to latency and availability needs. For more insights, explore virtualized infrastructure disaster recovery solutions to enhance your setup.

Choosing the Right VM Size for the Best Network Bandwidth Allocation

Azure gives network bandwidth according to the size of the VM. Bigger instances get more guaranteed throughput. The allocation can be anywhere from 0.5 Gbps for the smallest VMs to over 30 Gbps for the biggest compute-optimized and memory-optimized instances. Choosing VM sizes that meet your network needs is usually more cost-effective than getting more compute or memory resources than you need to get more bandwidth.

Make sure to look at Azure’s listed bandwidth allotments for each VM series and size to guarantee your chosen instances have enough network capacity. If your applications have uneven traffic patterns (more inbound than outbound traffic or the other way around), you should think about the bandwidth allocation model because some VM sizes have different limits for ingress and egress traffic. If you size your VMs correctly for network needs, you can greatly increase performance and optimize cloud spending.

Configuring Multiple Network Interfaces and Separating Traffic

If your application has complex and varying network traffic, you can configure multiple network interfaces (NICs) on your Azure VMs. This allows you to separate and optimize different types of traffic. By doing this, you can allocate bandwidth, apply security policies, and optimize routing for different types of traffic like management traffic, data replication, client connections, and backend services separately. Each type of traffic can be optimized without affecting other types of traffic. For more details, you can refer to optimizing network bandwidth on Azure.

Make sure that each interface is connected to the correct subnet and that the routing tables are set up correctly when you use multiple NICs. Configure application services to bind to specific interfaces, not all available network paths. This approach to segregating traffic is particularly useful for database servers, application gateways, or any VM that handles multiple distinct network functions with different performance characteristics.

Things to Keep in Mind for Network Virtual Appliances

When you’re setting up Network Virtual Appliances (NVAs) like firewalls, load balancers, or WAN optimizers in Azure, there are some specific things you should consider to optimize your network. These appliances often handle a lot of traffic, and if they’re not set up correctly, they can become a bottleneck. You should enable IP forwarding on NVA network interfaces and set up User Defined Routes (UDRs) to make sure traffic is routed correctly through the appliance.

If you’re dealing with high-throughput situations, it’s a good idea to go with NVA solutions that can handle Azure’s Accelerated Networking. You’ll also want to make sure they’re deployed on VM sizes that have enough bandwidth allocation. To ensure redundancy and boost throughput capacity, you might want to look into NVA clustering or scaling. It’s also vital to keep an eye on NVA performance metrics. If these components run out of resources, they can greatly affect the overall performance of your network.

Using Azure Network Watcher to Monitor Performance

For successful network optimization, you need to constantly monitor and analyze performance. Azure Network Watcher gives you a complete view of your VM network performance with features like Connection Monitor, Network Performance Monitor, and the ability to capture packets. These tools help you find bottlenecks, confirm optimization results, and monitor performance trends over time. To learn more about optimizing your network, check out this guide on optimizing network bandwidth.

Use Network Watcher’s Connection Monitor to keep an eye on latency, packet loss, and changes in topology between important application components. Set up alerts for performance drops to allow for proactive optimization. Network Watcher’s packet capture function offers in-depth visibility into traffic patterns and protocol behavior, which can help you discover specific optimization opportunities that you might have missed otherwise.

Adjusting MTU Size for Various Situations

The Maximum Transmission Unit (MTU) setup has a big influence on network performance, especially when dealing with data-heavy tasks. The MTU sets the maximum packet size that can be sent without being broken down into smaller pieces. Tweaking this based on the particular network path and needs of the application can enhance the rate of data transfer and decrease the processing overhead for both the system sending and the one receiving.

The network infrastructure of Azure is capable of supporting different MTU sizes, depending on the service and method of connectivity. By understanding these limitations and configuring your VMs properly, you can ensure that performance is optimal and avoid fragmentation issues that can greatly reduce throughput. MTU optimization is especially crucial for workloads that transfer large data blocks, such as data warehousing, backup operations, or content delivery.

How MTU Size Affects Network Performance

Having a larger MTU size means you can send more data in fewer packets. This is beneficial because it reduces the processing power needed for both the sender and receiver, which in turn improves the overall data flow and reduces latency. Every packet that is sent has an associated protocol overhead and processing cost. When you increase the size of the packet, you spread this cost over more data, making the process more efficient.

Nonetheless, when the MTU you’ve set is too large for the network path, your packets will either be fragmented or dropped, causing a significant decrease in performance. The best MTU size is the largest one that can travel the entire network path without being fragmented. In Azure environments, this is typically limited by the specific services in use, with values ranging from the standard 1500 bytes up to 4096 bytes for some configurations.

Setting Up Jumbo Frames Where Possible

For Azure virtual networks, particularly when it comes to VM-to-VM communication within the same region, jumbo frames with MTU sizes up to 4096 bytes are supported. Turning on these larger frame sizes can boost throughput by 10-20% for operations that are heavy on data. For Windows VMs, you can set up jumbo frame support through the advanced properties of the network adapter in Device Manager or by using PowerShell with the Set-NetAdapterAdvancedProperty cmdlet.

When dealing with Linux VMs, you should use the ip command to set the MTU (ip link set dev eth0 mtu 4096). You can make this change permanent by using your distribution’s network configuration files. Keep in mind that jumbo frames only work when all devices in the communication path can support the same MTU size. If you’re dealing with cross-region or hybrid connections, you may need to use standard MTU sizes to make sure all network segments are compatible.

Checking and Confirming the Best MTU Settings

Before rolling out MTU changes throughout your system, make sure to test the highest supported size for your specific network paths. Use tools like ping with the Don’t Fragment (DF) flag and gradually increasing packet sizes to find the largest MTU that works. For Windows, use commands like ‘ping -f -l 4096 target_ip’ while gradually adjusting the size value until you find the largest that works without fragmentation.

In Linux, you can perform similar tests using ‘ping -M do -s 4096 target_ip’. After you’ve found the best MTU, make sure to use it on all systems that need to communicate with each other. You can check if this improved the performance by using tools like iPerf3. After you’ve implemented this, keep an eye on the performance of your applications to make sure that it’s actually helping your production environment.

Strategies for Load Balancing and Traffic Distribution

It’s critical to have efficient load balancing in order to spread network traffic across multiple VMs. This maximizes throughput, guarantees reliability, and optimizes resource use. Azure offers a variety of load balancing options, each with its own set of optimization considerations. Comprehending these options and applying the right solution for your workload characteristics can greatly improve overall network performance.

Advanced load balancing strategies do more than just distribute connections. They also take into account things like session affinity, health probing behavior, and backend pool management to get the best performance possible. When you configure load balancing properly, you don’t just improve availability. You can also significantly increase throughput by directing traffic through the best paths and stopping individual VM bottlenecks.

Improving Internal Load Balancer Performance

Internal Load Balancers in Azure help manage traffic within virtual networks and provide several opportunities for optimization. For workloads with uneven traffic patterns, use floating IP (direct server return) to enhance performance by enabling response traffic to avoid the load balancer. To align with your application’s behavior, modify the frequency and timeout settings of the health probe. This prevents unneeded backend VM rotation due to incorrect health check failures. For more strategies on maintaining virtualized infrastructure, consider these disaster recovery solutions.

When working with TCP workloads, it’s recommended to enable TCP reset on idle timeout. This will ensure that inactive connections are properly closed, freeing up resources. It’s also important to configure idle timeout values that are appropriate for your application’s connection patterns. If the timeout value is too short, it could result in connections being terminated prematurely. On the other hand, if the timeout value is too long, it could lead to a depletion of connection resources. For the highest level of throughput, consider using the Standard SKU load balancer. This offers significantly higher performance limits compared to the Basic SKU.

Optimizing Traffic Patterns Between Virtual Machines Within Virtual Networks

Virtual Machines (VMs) within the same virtual network in Azure follow certain paths that can be optimized for better performance. When VMs communicate within the same subnet, the traffic flows directly without the need for a router, which provides the lowest possible latency. To take advantage of this, try to group VMs that frequently communicate with each other in the same subnet whenever possible.

When data is transferred between subnets, it must go through the router of the virtual network, which can cause a small delay. To reduce this, you should avoid creating unnecessary divisions between subnets that require data to go through the routing infrastructure. Also, keep in mind that network security groups (NSGs) are evaluated for both incoming and outgoing traffic, even if it’s within the same subnet. You should optimize these rules to reduce the processing overhead for common internal communication patterns.

Considerations for Traffic Across Different Regions

If your applications are spread across various Azure regions, you will need to pay even more attention to network optimization. This is because the latency is higher and there may be restrictions on the bandwidth. To direct users to the regional endpoint that is closest to them, you should use Azure Traffic Manager or Front Door services. Depending on the distribution needs of your application, you should configure the right routing methods, such as performance, weighted, and priority. For more insights on optimizing virtual environments, consider exploring VM customization environment tips.

If you need to synchronize data between regions, Azure ExpressRoute Premium is a good choice. It offers private connectivity that is more reliable and has more consistent latency than connections over the internet. Use compression for data transfers between regions to cut down on bandwidth requirements. Also, try to use asynchronous communication patterns when you can. This will help reduce the effect of inter-region latency on how your application performs.

Improving Performance with Virtual Network Peering

Virtual Network Peering in Azure allows virtual networks to connect directly, which is a critical component for multi-tier applications. The way peering is configured can greatly affect network performance, especially for applications with components spread over multiple virtual networks. By understanding how peering works and applying the right optimizations, you can make sure communication is efficient while keeping networks logically separate.

When designing your network, you should consider the different performance characteristics of both regional and global peering options. Regional peering offers near-direct connectivity with minimal latency overhead. On the other hand, global peering allows for communication across regions, but it also introduces additional latency based on geographical distance. If you optimize these connections based on the specific requirements of your workload, you could see significant performance improvements.

Best Practices for Peering Within a Region

Set up regional peering for virtual networks in the same Azure region to enable direct, low-latency connectivity. This type of connection provides the highest performance, with typical latency additions of less than 1ms compared to communication within a single virtual network. Only enable the “Allow Forwarded Traffic” option when it’s necessary for specific routing scenarios, in order to maintain optimal traffic paths.

For the best throughput between peered networks, make sure the VMs on both sides have the right network configurations. This includes Accelerated Networking and the right TCP settings. Use Network Watcher’s connection monitoring to keep an eye on peering connections and spot any unexpected drops in performance. If you have workloads with a lot of traffic between peered networks, think about merging them into a single, larger virtual network. This can help you avoid the small overhead that comes with peering.

Managing Latency in Cross-Region Peering

Global virtual network peering allows for connectivity between virtual networks in different Azure regions, but this results in latency based on geographical distance. To optimize applications, you should aim to reduce round trips between regions by using caching, data replication, or CDN solutions where suitable. You should also design application components to function independently as much as possible, to lessen the need for synchronous cross-region communication.

If you’re running an application that’s sensitive to latency and needs to span regions, choose Azure regions that are geographically close to each other. This will reduce the time it takes for network traffic to travel between them. You should also monitor the performance of your application’s communication across regions. This will help you spot any performance issues and optimize the way your application communicates. If your workloads need guaranteed performance and service level agreements (SLAs) between regions, you might want to consider using Azure ExpressRoute Global Reach instead of global peering.

Configuring Gateway Transit for the Best Routing

When you’re linking several virtual networks with on-premises networks or other cloud environments, make sure you set up gateway transit correctly to get the best routing paths. This setup lets a virtual network with a VPN or ExpressRoute gateway serve as a transit network. This means that connected networks can talk to each other without having to create direct connections between each pair of networks.

For better gateway transit performance, it’s important to place the transit virtual network in a region that is central to the networks that are communicating with each other. Make sure to put in place appropriate route tables to guarantee that traffic follows the most efficient routes. Also, keep an eye on gateway performance metrics to spot potential bottlenecks. If you’re dealing with high-throughput scenarios, choose gateway SKUs that have enough capacity to manage aggregated traffic from all connected networks without becoming a hindrance to performance.

Optimizing Network Performance Without Sacrificing Security

When optimizing network performance, it’s important to keep security in mind. Network security and performance optimization are often at odds, as security measures such as encryption, packet inspection, and traffic filtering can introduce processing overhead that can impact throughput and latency. However, with careful planning and configuration, it’s possible to maintain a strong security posture while minimizing the impact on performance. The key is to apply security controls strategically, based on the actual threat model, rather than applying maximum security indiscriminately.

There are several security services and features in Azure that can be optimized to provide effective protection without compromising performance. It’s important to understand how these services perform and how to configure them properly to avoid unnecessary overhead. By aligning security controls with business needs and threat models, you can ensure that your applications are protected without sacrificing the network performance they need to function optimally.

Optimizing Network Security Group Rules

Network Security Groups (NSGs) filter traffic by processing rules in order of priority. The number of rules, their complexity, and the order in which they are processed can all affect processing overhead and network latency. To optimize NSGs, try to reduce the number of rules you need. You can do this by consolidating similar rules using CIDR notation and service tags, instead of individual IP addresses or ports, whenever you can.

Arrange NSG rules so that the rules that are most often matched are given the highest priority, which will reduce the average time it takes to process them. Avoid creating rules that will never be matched because higher-priority rules are either blocking or allowing the same traffic. For applications that have multiple tiers, try to implement NSGs at the subnet level instead of the NIC level whenever you can, as this will reduce the total number of rule evaluations that are needed across the environment.

Evaluating the Performance Impact of Azure Firewall

While Azure Firewall offers a higher level of network protection, it does require additional processing power compared to Network Security Groups (NSGs). To ensure optimal performance when using Azure Firewall, choose the SKU that best fits your throughput needs—Standard SKU for general protection or Premium SKU for a higher level of throughput and added security features. Set up rules to reduce unnecessary inspection, such as permitting trusted Microsoft service tags without deep packet inspection. For more details on optimizing network performance, you can refer to Azure’s TCP/IP performance tuning guide.

You should use Azure Firewall in a hub-spoke network topology to centralize your protection and reduce the number of inspection points. This setup provides thorough security and allows spokes to communicate directly for traffic that doesn’t need to be inspected by the firewall. Keep a close eye on Azure Firewall metrics to spot potential bottlenecks and tweak rules or capacity as necessary to keep performance at its best.

Keeping Your Site Safe From DDoS Attacks Without Slowing Down Performance

The Azure DDoS Protection feature is designed to keep your applications safe from distributed denial-of-service attacks. However, you need to set it up correctly to ensure it doesn’t affect your regular traffic. You should use the Standard tier for your production workloads, which gives you access to more advanced mitigation capabilities and tuning options. You should also set up your alerting thresholds based on what’s normal for your application’s traffic to avoid false positives when you have a legitimate traffic spike. For more information on optimizing your network, refer to Azure’s guide on network bandwidth optimization.

To ensure your application runs at its best, you should create protection policies that are specific to your application, with custom TCP/UDP thresholds that match the characteristics of your workload. This way, protection will only kick in when actual attack traffic is detected, not during regular operation. It’s also important to regularly check telemetry data and adjust protection parameters as your application’s traffic patterns change, to keep the right balance between security and performance.

Checking and Confirming Network Performance Enhancements

It’s crucial to consistently measure to ensure the network enhancements are working as expected. If not validated correctly, there’s a chance that the changes made will provide little to no benefits or could even negatively impact performance in ways not foreseen. By setting a baseline metric before the enhancement and then testing comparatively after the changes, it provides concrete proof of improvement and highlights areas that need more work.

It’s crucial to use both synthetic tests, which focus on individual network features, and real-world application performance measurements for a well-rounded validation strategy. This two-pronged approach guarantees that theoretical network enhancements result in real-world business advantages. Regular performance testing should be incorporated into your operational routine to detect any performance decline over time and to continually improve optimization tactics.

Tools for Testing Bandwidth and Throughput

When it comes to measuring the raw throughput of a network, iPerf3 is the go-to tool for most industry professionals. It’s available for both Windows and Linux. To get the most out of available bandwidth, configure iPerf3 to test with multiple parallel streams by using the -P flag. You can also play around with different TCP window sizes by using the -w flag to find the best settings. For those working in production environments, it’s a good idea to set up automated tests between important VM pairs. Schedule these to run periodically so you can keep an eye on performance trends.

With Azure, you don’t need to install any additional tools to monitor your network performance. The connection monitor feature of Network Watcher can track throughput between VMs or to external endpoints with minimal configuration. For a more comprehensive analysis of network performance, you can use commercial tools like SolarWinds Network Performance Monitor or NetOps by Perimeter 81. These tools offer detailed metrics and visualization capabilities that make it easier to identify bottlenecks and opportunities for optimization.

Methods for Measuring Latency

Latency testing can be performed in a basic sense with simple ping tests. However, to gain a true understanding of how an application performs in the real world, more advanced measurements are needed. Tools like MTR (My Traceroute) or WinMTR can provide a detailed analysis of the path with latency statistics for each hop. This can help identify the specific segments that are causing delays. For testing TCP applications, use tools like tcpping. These measure the actual times for establishing application-layer connections, rather than just ICMP echo responses. For more insights on optimizing virtualized infrastructure, consider exploring disaster recovery solutions and strategies.

When you have a distributed application that has many parts, you should use distributed tracing. You can use tools like Azure Application Insights or Jaeger to do this. These tools will help you see how the network performance affects the total response time of the application. They can also help you find specific communication paths that need to be optimized. You should measure latency during both busy and slow times to see how different loads affect performance.

Optimization: Before and After Performance Benchmarking

It’s important to set up a consistent benchmarking methodology that you can use before and after you make optimization changes. Make sure to document the test parameters, network conditions, and VM states during the testing phase to make valid comparisons. It’s also a good idea to run multiple test iterations to account for normal performance variations. Use statistical measures like average, median, and 95th percentile values instead of just relying on single measurements.

When conducting thorough benchmarking, you should consider a variety of performance aspects. Don’t just focus on the highest throughput. You should also consider latency when under load, the rate of connection establishment, and packet loss during congestion. To get an overall view of network health, create a performance scorecard that combines these metrics. This method will give you a more comprehensive understanding of the benefits of optimization than if you were to only concentrate on the highest throughput numbers.

Optimizing Network Configuration for Azure VM Migration

When you’re moving your workloads to Azure, it’s a great time to put network optimizations in place from the start, instead of trying to add them in after everything’s already up and running. Many network designs that work well on-premises don’t translate perfectly to the cloud, and need some tweaking to get the best performance. By planning ahead during the migration phase, you can avoid performance issues and reduce the likelihood of needing to make disruptive changes after your applications are already in production.

Many businesses copy their on-site network setups to Azure without thinking about how to optimize them for the cloud. This can lead to poor performance and needless complexity. A cloud-ready strategy questions basic networking assumptions, uses Azure-specific features, and designs the network in line with cloud architecture principles. This strategy not only improves performance right away, but also makes it easier to scale and optimize the network in the future.

Adjusting On-Site Network Designs for the Cloud

On-site networks typically depend on physical topology, hardware-based security appliances, and static routing that doesn’t directly translate to cloud environments. Instead of directly transferring existing network designs, break down network requirements to their basic needs—connectivity, security, and performance—and reconstruct using cloud-native approaches. Replace hardware load balancers with Azure Load Balancer or Application Gateway, physical firewalls with NSGs or Azure Firewall, and static routes with Azure routing features.

Think about how you plan IP address space, divide subnets, and isolate networks from a cloud perspective. Azure virtual networks are different from physical networks, which impacts broadcast domains, routing behavior, and security boundaries. Use hub-spoke topologies with centralized shared services instead of flat network designs to make it easier to manage and scale. This change in architecture lets you use Azure’s software-defined networking capabilities more effectively.

Optimizing Network Resources for Cost Efficiency

Cloud networking resources can significantly affect costs through bandwidth charges, gateway hours, and service utilization. It is important to size these resources correctly to ensure you get the performance you need without paying for resources you don’t need. Instead of simply replicating your existing configurations in the cloud, analyze the actual traffic patterns from your on-premises environments to determine what your bandwidth requirements really are. After you have migrated, monitor the actual usage and adjust the resources to match the actual usage rather than the theoretical maximums.

Choose the right SKUs for your network components based on your performance needs. For instance, you might want to choose Basic Load Balancer for development environments and Standard for production. Or, you could size ExpressRoute circuits based on your actual bandwidth needs instead of the capacities of your existing on-premises circuits. Use Azure Network Watcher flow logs to find resources that are being underused. You can then downsize or consolidate these resources to optimize costs without hurting performance.

• Right-size VPN and ExpressRoute gateways based on actual throughput needs, not default selections
• Consolidate network security groups at subnet level rather than creating per-VM NSGs when possible
• Optimize Public IP usage by sharing load balancers across compatible services
• Select appropriate Load Balancer SKUs based on environment requirements
• Implement auto-scaling for Application Gateway to match actual traffic patterns

Automation Scripts for Consistent Network Configuration

Implementing network optimizations consistently across multiple VMs and environments requires automation. Develop ARM templates, Terraform configurations, or Azure CLI scripts that incorporate best practices and optimizations by default. These automation assets ensure that all deployed resources follow standardized performance-optimized configurations without requiring manual intervention for each VM or network component.

Post-deployment scripts can be included to optimize the operating system on both Windows and Linux VMs. These scripts can automatically adjust TCP parameters, configure RSS settings, and optimize network adapter properties during the provisioning process. By storing these automation tools in version control systems, optimization techniques can be continuously improved while maintaining deployment consistency. Perimeter 81’s NetOps provides tools that can automate many of these network optimization tasks, ensuring consistent configuration across your entire Azure environment.

Common Questions

Optimizing the network for Azure virtual machines is a technical process with many factors and settings to consider, which can lead to questions during setup. This FAQ answers common questions and provides practical advice from real-world experience optimizing Azure VM networks. The answers come from Microsoft’s official recommendations and from best practices used by organizations that successfully run high-performance workloads in Azure. For more detailed guidance, you can refer to Microsoft’s recommendations on optimizing network bandwidth.

If you encounter unique situations that this guide doesn’t cover, I recommend checking out Azure’s official documentation or getting in touch with Microsoft’s support team for personalized advice. Network optimization isn’t a one-and-done deal. It’s an ongoing task that changes as Azure rolls out new features and as your application’s needs shift. By routinely revisiting your strategy, you can make sure you’re taking advantage of the most recent features and best practices for your particular workloads.

What is the highest network throughput Azure VMs can achieve?

There’s a wide range of maximum network throughput depending on the VM series and size. Currently, the VMs that perform the best can reach up to 30 Gbps, specifically the Mv2 series optimized for memory, FSv2 series optimized for computing, and Dv4/Ev4 series optimized for general purposes in their largest sizes. Other VM series usually vary from 1-16 Gbps based on size and family. It’s worth mentioning that to achieve these maximums, you need to enable Accelerated Networking and optimize the guest OS properly.

As time goes on, Azure continues to roll out new VM sizes that offer improved networking capabilities, which means the maximum throughput is always on the rise. To stay up-to-date, you can refer to the Azure documentation for your specific VM series. Alternatively, you can use the ‘az vm list-sizes’ command along with the ‘–query’ parameter to filter for network properties. Keep in mind that if you want to reach the maximum theoretical throughput, you need to have applications that have been optimized to use multiple parallel connections. For those interested in enhancing their virtualized environments, exploring disaster recovery solutions can be beneficial.

Are all VM sizes compatible with accelerated networking features?

No, Accelerated Networking isn’t available for all VM sizes. It’s generally available for VM series with 2 or more vCPUs, but the specific requirements can change depending on the family. Basic A-series VMs, Av1-series, and most B-series (burstable) VMs don’t support Accelerated Networking. Also, the first-generation VM series like D1-D3v1 don’t have support. For the most up-to-date information, you should check the Azure documentation that’s specific to your VM series or use the ‘az vm list-skus’ command to query capabilities by region.

Remember, Accelerated Networking may not be supported by the smallest sizes (typically those with less than 2 vCPUs) even within supported families. Before selecting VM sizes, verify Accelerated Networking support when planning deployments that require optimal network performance. Consider upgrading to supported VM series to gain significant network performance improvements if you’re running workloads on unsupported sizes. For additional insights on optimizing network performance, explore virtualized infrastructure strategies.

How can I fix network performance problems in Azure Virtual Machines?

If you are experiencing network performance issues with Azure VMs, it’s important to take a systematic approach to troubleshooting. Start by checking the basic configuration: make sure Accelerated Networking is turned on, verify that the size of your VM meets your bandwidth needs, and ensure that there are no NSG rules that could be restricting traffic. You can use the Connection Monitor feature in Azure Network Watcher to measure latency and detect packet loss between endpoints. For a more detailed analysis, you can capture packets using the packet capture feature in Network Watcher and use tools like Wireshark to identify any protocol problems or inefficient communication patterns.

Once you’ve confirmed that the basic configuration is correct, you should then investigate the settings at the operating system level. For Windows virtual machines, you should check the configuration of RSS, TCP parameters, and the properties of the network adapter. For Linux virtual machines, you should verify the kernel parameters that are related to TCP buffers and congestion control. You can use tools like iPerf3 to help you separate network issues from application issues by testing the raw throughput. You should also compare the performance between different pairs of endpoints to determine whether the issues are specific to certain network paths or whether they affect all communication.

Is it possible to enhance network performance for containers running on Azure VMs?

Indeed, you can enhance container networking on Azure VMs, but you need to bear in mind certain considerations that go beyond standard VM optimization. To begin with, make sure the host VM has Accelerated Networking enabled and is correctly sized for your container workload’s aggregate network requirements. When deploying Docker, use the ‘–net=host’ option where security considerations permit, as this offers the best performance by bypassing container network virtualization layers. For more detailed tips, check out this guide on Citrix Hypervisor security best practices.

When working with Kubernetes environments on Azure Virtual Machines, it’s important to choose the right network plugins based on your performance needs. While the Azure CNI plugin often provides better performance than kubenet, it does require more planning when it comes to IP address space. Make sure you configure the Kubernetes node VM sizes to accommodate the combined network needs of all pods that could run on each node. Plus, think about using the Direct Server Return (DSR) load balancing mode with Kubernetes services to make the most of traffic paths for responses.

• Ensure container host VMs have Accelerated Networking enabled
• Size host VMs based on aggregate container network requirements
• Use host network mode when possible for maximum performance
• Select appropriate CNI plugins in Kubernetes environments
• Monitor container-specific metrics to identify network bottlenecks

What’s the difference between network optimization for Windows and Linux VMs?

Windows and Linux VMs require different optimization approaches due to fundamental differences in their network stacks and configuration mechanisms. Windows optimization primarily focuses on RSS configuration, TCP offload settings, and registry parameters controlling the TCP/IP stack. These adjustments are typically made through PowerShell, the registry editor, or Device Manager. Windows Server provides fewer tuning parameters than Linux but offers graphical tools that simplify configuration, as highlighted in Citrix Hypervisor Security Best Practices.

Linux provides a high level of control over the network stack through sysctl parameters. Some of the common optimizations in Linux include modifying tcp_rmem/wmem values, changing congestion control algorithms, and tuning network interface queues. These changes can be made via sysctl.conf files or directly through the /proc filesystem. Linux also has a wide range of command-line diagnostic tools such as ss, ip, and ethtool that provide a detailed insight into network operation.

Even though there are differences, the main goals of optimization are the same: to increase throughput, reduce latency, and make sure resources are used efficiently. Both platforms can take advantage of Azure features like Accelerated Networking, the right VM size, and optimized application communication patterns. The best optimization strategy uses both tuning that is specific to the platform and configurations that are specific to Azure to get the best performance.

If you’re looking for a way to optimize your network, improve visibility, and manage security across your Azure environment, you might want to think about using Perimeter 81’s NetOps. Our platform gives you the tools to monitor, troubleshoot, and optimize VM network performance, all while keeping your security controls strong.