Best Tools to Monitor MPLS Networks

MPLS networks are one of the most popular types of WAN service. They are very efficient and kind of offer a combination of the best of routed networks and switched networks. They are fully meshed services where all sites are reachable from all others without requiring that you set up specific routes. But they still use the same underlying technology as any other type of WAN circuit and they supper from the same issue. In particular, like any other WAN circuit, they can get congested and, when they do, their performance is horribly degraded. For that reason, one needs to keep a close eye on them. This is why we’re glad to introduce the very best tools to monitor MPLS networks that we could find.

Before we dig into the core of our subject, we’ll first briefly explore MPLS networks, what they are, how they operate and what makes them different from other types of WAN circuits. Then we’ll talk about monitoring tools and how they work. Knowing that could help you pick the best tool for your specific needs. And finally, we’ll give you a brief review of some of the best tools to monitor MPLS networks.

MPLS Networks In A Nutshell

First, let’s see what MPLS is not. MPLS, or Multi-Protocol Label Switching, is not a type of service. It is rather a technology that is used by service providers to deliver different types of services. MPLS can be used, for instance for IPVPN services or for Metro Ethernet services.

In a “conventional” network, the path between any two points is not known by any of the routers handling the traffic. Packets are marked with their destination address and each successive router only know about the best next hop where to send it. It doesn’t know or care what the next hop will do with it. Given that, each successive router must make a decision based on routing tables as to where to send each packet next. This, you could imagine, can take some time.

With MPLS networks, things work a little differently. Without going too technical, the routes between any two points an MPLS network are calculated in advance and are stored on each router. When a packet enters the networks, it is marked with an identifier for that destination called a Forwarding Equivalence Class, or FEC. From there, each successive router only has to look up the FEC in a table to find the next hop’s address. This is much more efficient than making a routing decision.

We could spend hours describing MPLS networks and how they operate and what makes them so efficient but it wouldn’t help you when it comes to monitoring them. For now, let’s concentrate on how network monitoring tools work.

How Network Monitoring Tools Work

Network monitoring tools almost always use the Simple Network Management Protocol, or SNMP to do their magic. Although it bears a somewhat misleading name, SNMP is a relatively complex protocol. Introduced about 30 years ago, it is at its core a communication protocol that allows network administrators to manage, monitor, and diagnose devices from a remote location. For the sake of this discussion, we’ll ignore the management side of the protocol but let’s have a look at how the monitoring side of SNMP works. We’ll try to keep is as simple and non-technical as possible.

SNMP is built into the firmware of many—actually most—networking equipment. SNMP-enabled devices expose some of their operational parameters. A suitably configured SNMP monitoring or management system can then access them. Some parameters are read-only while others can be modified. For monitoring purposes, the read-only parameters are the ones of interest. They are referred to as OIDs, an acronym for Object IDentifiers. In the context of monitoring MPLS networks, some of these OIDs are specifically interesting. SNMP-enabled networking devices—such as MPLS routers—have a pair of OIDs for each interface that count the bytes in and the bytes out.

Monitoring tools read these counters to measure interface traffic in bits per second. Here’s how they do it. The monitoring system will poll each device at known intervals (with 5 minutes being the most common), read the value of the bytes in and out counters, and store them in some form of database or file. From then on, is just mathematics. The previous value of the counter is subtracted from the current one, giving the total number of bytes in five minutes. This number is multiplied by eight to get the number of bits and divided by 300 (the number of seconds in five minutes) to obtain the average bandwidth utilization over the last five minutes in bits per second. This information is also stored in a database and used to plot graphs or tables of its evolution in time.

One important aspect here is that what you get are average values. They are not real-time actual readings. This means that, for instance, a given circuit could be used at 100% of its capacity for 150 seconds and be unused for 150 seconds and it would display a 50% utilization rate. This makes this time of monitoring better suited for long-term trend analysis that on the spot debugging. Network traffic analyzers and packet capture tools are better suited for that.

The Tools For Monitoring MPLS Networks

Circuits using the MPLS technology are no different from those using other technologies. For that reason, The same tools can be used on MPLS networks as on other networks. Our list of the best tools for monitoring MPLS networks features a combination of paid and free tools. Some are more feature-rich than others but don’t assume that products with not as many features are not as good. It all depends on your needs more than anything else. If, for instance, all you want is to keep historical utilization data for forecasting purposes, you won’t mind a product with limited alerting capabilities.

1. SolarWinds Network Performance Monitor 

Our list begins with an excellent product from SolarWinds, a well-known name among many network administrators. With over 30 full-featured tools, the company offers a solution for almost every need. In particular, SolarWinds is, for instance, known to make one of the best NetFlow collectors and analyzers. SolarWinds is also known for making excellent free tools that address specific needs such as a subnet calculator or a TFTP server.

The company’s flagship product, the SolarWinds Network Performance Monitor, or NPM as it is often called, is packed with great features, one of the main ones being its simplicity. But we don’t mean simple as incomplete; we mean simple as easy. The product is easy to use and easy to install. You won’t need to go back to school to learn how to use it. You probably won’t even have to read the documentation–although we strongly suggest you do. This tool is also highly flexible and its dashboard, views, and charts can be customized at will. Setup requires little effort and you can start monitoring within minutes. NPM is also highly scalable and it can be used to monitor networks of almost any size from the smallest ones to huge corporate networks spanning multiple sites.

The SolarWinds Network Performance Monitor periodically polls your networking equipment to read their interface counters, computes the bandwidth utilization, and displays it as graphs showing its evolution over time. Configuring the tool is easy and only requires that you specify a device’s IP address and then pick which parameter you want to monitor. An auto-discovery engine makes initial setup super easy. The Solarwinds Network Performance Monitor also has many advanced features. It can, for instance, built network maps. It can also display the critical path between two devices, a handy feature when troubleshooting slowdowns.

Price for the SolarWinds Network Performance Monitor starts at $2 995 for up to 100 monitored elements and varies according to the number of monitored elements. If you’d rather try the product before buying it, a free and device-unlimited 30-day trial version can be downloaded from SolarWinds.

2. PRTG

The Paessler Router Traffic Grapher, or PRTG, claims to be one of the easiest and fastest monitoring tools to set up. According to Paessler, you could be up and running within minutes. Part of the product’s speed and ease of set up comes from its auto-discovery feature. After installation, PRTG scans your network and automatically adds the components it finds.

PRTG is supplied with several user interfaces. This is another one of the tool’s strength. You can choose between a native Windows console, an Ajax-based web interface or mobile apps for Android or iOS. And the mobile apps exploit their platform’s capabilities and will, for instance, let you scan a QR code printed on a label by the software and affixed to your equipment to quickly view its status. PRTG is one of the few tools that use more than just SNMP to do its monitoring. As such, it can monitor many more parameters in addition to bandwidth utilization using protocols such as WMI, NetFlow, and Sflow. Overall, PRTG is an excellent tool.

3. ManageEngine OpManager

ManageEngine is another well-known maker of network administration tools. And the ManageEngine OpManager allows you to monitor routers, switches, firewalls, servers, and virtual machine for fault and performance. Network device performance is monitored in quasi-real time and it can be viewed on live dashboards and graphs. The tool doesn’t stop at bandwidth utilization, though. Critical metrics like packet loss, errors, and discards are monitored. The system will also monitor physical and virtual servers’ performance metrics such as availability, CPU load, and disk space and memory utilization.

With more than 100 built-in reports which can be scheduled, customized, and exported at will, reporting is another one of OpManager’s best features. The software is available in three versions: Free, Essential and Enterprise. They differ in the number of devices they can monitor–from 10 for the Free version to 10 000 for the Enterprise–and their feature set, with higher versions sporting additional advanced features.

4. Cacti

Cacti is probably one of the most-used and one of the oldest free and open-source monitoring platforms. And while it might not be as feature-rich as some commercial products, it is still an excellent tool. And the fact that the system has been there for over 20 years–and still is, virtually unchanged–is a testament to its value. Although the tool’s web-based user interface has a definite vintage feel, it is well laid out and easy to use. The system typically uses SNMP polling but custom scripts can be devised to get data from virtually any source.

Cacti’s principal strength is in polling devices and graphing their data on web pages. And while it does that really well, that’s about all it will do. However, if you don’t need alerting or other extras, the product’s simple and clean design might be just what you need. Furthermore, since the software is open-source and almost entirely written in the PHP language, it is highly customizable and you could adapt it to our specific needs by adding any required functionality.

One of Cacti’s biggest strengths is its templates. There is, for example, a built-in template for Cisco switches that already includes most of the elements you might want to monitor on these devices. And in addition to device templates, there are also graph templates and data source templates. Together, the wide variety of available templates makes configuring the tool much easier and quicker. You can also custom build device-specific templates yourself if a suitable one doesn’t already exist. And there are many device-specific templates that can be downloaded either from each respective device manufacturer’s website or from community-driven Cacti forums.

5. Observium

Observium is a monitoring platform with many features, some of the main ones being its low-maintenance and auto-discovery. It supports a vast array of device types, platforms, and operating systems from most major vendors including, among others, Cisco, Microsoft, Linux, HP, Juniper, Dell, FreeBSD, Brocade, Netscaler, and NetApp. The product’s primary goal is providing its users with a beautiful, intuitive, and simple yet powerful user interface showing the health and status of your network.

Observium has a lot more to offer than just bandwidth monitoring. Its accounting system will, for instance, measure total monthly bandwidth usage in the 95th percentile or in total transferred bytes. It also has an alerting function with user-defined thresholds.

Observium is only available for Linux. It is easy to set up and it almost configures itself. The main drawback is obtaining the software which can be a challenge for some. Instead of having a clearly labeled download page on Observium’s website, what you’ll find instead are detailed installation instructions for many different Linux distributions. Each set of instructions does include the links to get the package for that specific distribution. As unusual as it may be, it actually makes a lot of sense and it guides users into downloading the right package for their specific distro.

6. Nagios

Nagios is available in two different versions. First, there is a free, open-source version called Nagios Core that one can download and which can be used by anyone. There is also a commercial product called Nagios XI. This commercial product has more features but they both share the same core engine. This makes the free edition a very potent tool within its feature limitations, of course. Nagios’ original purpose was up or down monitoring but it has evolved into a tool which can easily monitor many device’s operational parameters.

One of the best features of Nagios–especially the open-source version–is its community support. It is simply impressive, especially for a community-based offering. Also, several community-developed plugins, front ends, and add-ons are available directly from the Nagios website. If you want more functionality, including MPLS monitoring, you’ll have to go for the paid Nagios XI which features bandwidth monitoring and a handful of other useful features. A free trial version of Nagios XI is available if you want to see for yourself what this tool can do for you.

7. WhatsUp Gold

WhatsUp Gold from Ipswitch is another tool that’s been around for a while. This tool’s primary function used to be monitoring system availability rather than operational parameters. This is where its name comes from. WhatsUp Gold would be used to tell what’s up and what’s not. One of it’s biggest advantage is that it has one of the best alerting systems which can be configured to transmit alerts using a multitude of ways including email and SMS.

Today, WhatsUp Gold does a whole lot more than just monitoring the up and down status of devices. It is a true monitoring platform that can also measure bandwidth usage and check that services are responding. It will, for example, monitor the availability of Exchange and SQL servers, Active Directory, IIS and Apache Web services. And if your server farm is cloud-based, WhatsUp Gold can also be used to monitor AWS or Azure installations.

8. Zabbix

Last on our list is yet another open-source product called Zabbix. This tool has a highly professional look and feel, much like what you’d expect from a commercial product. But its good-looking web-based interface is definitely not its only strength. The product also sports an impressive feature set. Zabbix will monitor most network-attached devices, not just networking equipment. that can make it an excellent option if you also want to monitor servers, for instance.

Zabbix uses both SNMP and the Intelligent Platform Monitoring Interface (IMPI) for monitoring devices. You can use it to monitor bandwidth, device CPU and memory utilization, general device health as well as configuration changes. In addition, Zabbix features an excellent and completely customizable alerting system which will not only send email or SMS alerts but also run local scripts.