Microsoft Azure provides several solutions that allow you to monitor network resources, not only for cloud environments, but even in the presence of hybrid architectures. That are cloud-based features, to check the health of your network and connectivity to your applications. Furthermore, they give detailed information about network performance. This article will be made an overview of the various solutions such as the main features, needed to orient the use of the network monitor tools most appropriate for your needs.

Network Performance Monitor (NPM) is a suite that includes the following solutions:

• Performance Monitor
• ExpressRoute Monitor
• Service Endpoint Monitor

In addition to the tools included in the Network Performance Monitor (NPM) you can use Traffic Analytics and DNS Analytics.

Performance Monitor

The most commonly used approach is to have hybrid environments with heterogeneous networking, that allows you to connect your own on-premises infrastructure with the environment implemented in the public cloud. In some cases you may also have different cloud providers, that make the network infrastructure even more complicated . These scenarios require the use of flexible monitor tools that can work across on-premises, in cloud (IaaS), and in hybrid environments. Performance Monitor has all of these characteristics and thanks to the use of synthetic transactions, provides the ability to monitor, almost in real time, the network parameters to get performance information, like packet loss and latency. Furthermore, this solution allows to easily locate the source of a problem in a specific network segment or identifying a particular device. The solution requires the presence of the OMS agent and keeping track of the retransmission packets and the roundtrip time, is able to return a graph of easy and immediate interpretation.

Figure 1 - Hop-by-hop chart provided by Performance Monitor

Where to install the agents

The installation of the agent of Operations Management Suite (OMS) is necessary on at least one node connected to each subnet from which it intends to monitor the connectivity to other subnets. If you plan to monitor a specific network link you must install agents on both endpoints of the link. In cases where you do not know the exact network topology, one possible approach is to install agents on all servers that hold critical workloads and for which you need to monitor your network performance.

The Cost of the Solution

The cost of the feature Performance Monitor in NPM is calculated on the basis of the combination of these two elements:

• Monitored Subnet link. To obtain the costs for monitoring of a single subnet link for one month, you can see Ping Mesh.
• Data volume.

For more details please visit the Microsoft's official page.

ExpressRoute Monitor

Using ExpressRoute Monitor it is possible to monitor the end-to-end connectivity and verify the performance between on-premises environment and Azure, in the presence of ExpressRoute connectivity with Azure Private peering and Microsoft peering connections. The key features of this solution are:

• Auto-detection of the circuit ExpressRoute associated with your subscription Azure.
• Detection of network topology.
• Capacity planning and bandwidth usage analysis.
• Monitoring and alerting both the primary and the secondary path of the circuit ExpressRoute.
• Monitoring connectivity towards the Azure services such as Office 365, Dynamics 365 using ExpressRoute as connectivity.
• Detection of possible deterioration of connectivity with the various virtual network.

Figure 2 – Topology view of a VM on Azure (left) connected to a VM on-prem (right), via ExpressRoute

Figure 3 - Trend on the use of the bandwidth and latency on the ExpressRoute circuit

Where to install the agents

In order to use ExpressRoute Monitor you need to install an Operations Management Suite agent on a system that resides on Azure virtual network and at least one agent on a machine attested on the subnet on-premises, connected via private peering of ExpressRoute.

The Cost of the Solution

The cost of ExpressRoute Monitor solution is calculated based on the volume of data generated during the monitoring operations. For more details please visit the specific section in the cost page of NPM .

Service Endpoint Monitor

Using this solution, you have the ability to monitor and test the reachability of your services and your applications, almost in real time, simulating user access. You also have the ability to detect network side performance problems and identify the problematic network segment.

Here are reported the main features of the solution:

• It does the monitor end-to-end of the network connections to your applications. The monitor can be done by any endpoint "TCP-capable" (HTTP, HTTPS, TCP, and ICMP), as websites, SaaS applications, PaaS applications, and SQL databases.
• It correlates application availability with network performance, to precisely locate the degradation point on the network, starting from the user's request until the application.
• It tests applications reachability from different geographical location .
• It determines the network latencies and lost packets to reach the applications.
• It detects hot spots on the network that can cause performance problems.
• It does the monitor of the availability of applications Office 365, through specific built-in test for Microsoft Office 365, Dynamics 365, Skype for Business and other Microsoft services.

Figure 4 - Creating of a Service Connectivity Monitor test

Figure 5 – Diagram showing the topology of the network, generated by different nodes, for a Service Endpoint

Where to install the agents

To use Service Endpoint Monitor you must install the Operations Management Suite agent on each node where you want to monitor network connectivity to a specific service endpoint.

The Cost of the Solution

The cost for using Service Endpoint Monitor is based on these two items:

• Number of connections, where the connection is understood as reachability test of a single endpoint, from a single agent, for the entire month. In this regard you can see Connection Monitoring in the cost page.
• Volume of data generated by the monitor. The cost is obtained from cost page of Log Analytics, in the section Data Ingestion.

Traffic Analytics

Traffic Analytics is a totally cloud-based solution, allowing you to have an overall visibility on network activities that are undertaken in the cloud environment. In Azure to allow or deny network communication to the resources connected with Azure Virtual Networks (vNet) it uses the Network Security Group (NSG), containing a list of access rules. The NSGs are applied to network interfaces connected to the virtual machines, or directly to the subnet. The platform uses NSG flow logs to maintain the visibility of inbound and outbound network traffic from the Network Security Group. Traffic Analytics is based on the analysis of NSG flow logs and after an appropriate aggregation of data, inserting the necessary intelligence concerning security, topology and geographic map, can provide detailed information about the network traffic of your Azure cloud environment.

Using Traffic Analytics you can do the following:

• View network activities cross Azure subscriptions and identify hotspots.
• Intercept potential network security threats, in order to take the right remedial actions. This is made possible thanks to the information provided by the solution: which ports are open, what applications attempt to access to Internet and which virtual machines connect to unauthorized networks.
• Understand network flows between different Azure regions and Internet, in order to optimize their deployment for network performance and capacity.
• Identify incorrect network configurations that lead to having incorrect communication attempts.
• Analysis of the VPN gateway capabilities or other services, to detect problems caused by over-provisioning and underutilization.

Figure 6 – Traffic Analytics overview

Figure 7 - Map of Active Azure Regions on the subscription

DNS Analytics

DNS Analytics solution is able to collect, analyze and correlate logs of DNS and provides administrators the following features:

• Identifies clients that try to resolve domains considered malevolent.
• Finds records that belong to obsolete resources.
• It highlights domain names frequently questioned.
• View the load of requests received by the DNS server.
• It does the monitor of dynamic DNS registrations failed.

Figure 8 – Overview of DNS Analytics solution

Where to install the agents

The solution requires the presence of the OMS agent or the Operations Manager agent installed on each DNS server to be monitored.

Conclusions

With increasing complexity of network architectures in hybrid environments, consequently increases the need to be able to use tools able to contemplate different network topologies. Azure provides several cloud based tools and integrated into the fabric, such as those described in this article, that allow you to fully and effectively monitor the networking of these environments. Remember to test and evaluate free Operations Management Suite (OMS) you can access this page and select the mode that is most appropriate for your needs.