A couple of years ago, I was asked to consult on a project: an organization was getting a lot of bandwidth from their ISP but they couldn’t figure out why connecting to the Internet was still very slow. After spending a few days on the client’s site, I eventually discovered that the source of their problem was a faulty router interface that was dropping more than half of the bandwidth they were receiving from their ISP.
Why did I tell that story? Well, if that organization had been monitoring the bandwidth on their network, perhaps I would not have stayed that long looking for the problem. In fact, maybe they would not have needed to call me in to find the problem (not like I’m complaining).
The question then arises: Why do we even need to monitor the bandwidth on a network?
There are several reasons some of which are as follows:
- Troubleshoot Network Performance: Network Bandwidth monitoring can help you identify performance issues on a network like in the example I gave above. For example, by monitoring network bandwidth, you may find out that a particular computer on the network is consuming (hogging) so much bandwidth which may be an indication of a worm or virus. In other cases, you'll find that analyzing Wifi Access Points and connected Clients that are using it will help you determine who is potentially abusing it.
- Network Capacity Planning: By monitoring network bandwidth, you are able to plan ahead regarding the bandwidth capacity that your network requires. For example, when you start out your network, you may have a few hundred devices and require a hypothetical 100 Mbps of bandwidth. As the network grows in size, you may find out (through monitoring) that the 100 Mbps is being maxed out at peak periods and should be upgraded.
- Monitoring Agreed-Upon Bandwidth: When you purchase bandwidth (e.g. Internet) from Internet Service Providers (ISPs), they guarantee that the speed will be at a certain level (usually expressed in Megabits per second, Mbps). By monitoring network bandwidth, you can determine if your ISP is really giving you the bandwidth that was agreed upon or if they are failing on their Service Level Agreement (SLA).
As the name implies, a Network Bandwidth Monitoring tool lets you keep an eye on bandwidth and traffic usage on the network. These tools will usually be able to report on single nodes (e.g. traffic usage by a single computer) or on interfaces (e.g. FastEthernet0/0 interface on a router). Some of these tools will be able to present this information in graphs and also sort devices (or IP addresses) based on top bandwidth “consumers”.
To get this traffic usage information, several methods can be employed including packet capturing, Simple Network Management Protocol (SNMP) or NetFlow (or some other flow related technology).
There are several tools that can be used for Network Bandwidth/Traffic Monitoring and the ones we will be discussing in this article are as follows:
- Solarwinds Network Traffic Analyzer
- Solarwinds Real-Time Bandwidth Monitor
- PRTG Network Monitor
- ManageEngine
- nTop-Ng
- Cacti
- BandwidthD
Top Network Bandwidth Monitoring Tools:
Some of these tools are standalone network bandwidth monitoring tools while others are all-in-one network monitoring solution that include bandwidth monitoring amongst other features.
1. Solarwinds Real-Time Monitor
Solarwinds is a company that provides a lot of IT Management tools. In terms of Network Bandwidth Monitoring, Solarwinds has two solutions:
– The freeware Real-Time Bandwidth Monitor.
– The more robust (and commercial) NetFlow Traffic Analyzer, which we'll get to further down.
Solarwinds provides a free tool to use to monitor, in real-time, the bandwidth usage of the interfaces of several devices. It actually a very simple tool to use: enter the IP address of the device along with the right SNMP credentials, choose the interface(s) to monitor and that’s it – you get a graph showing the bandwidth usage in real time. You can even customize how often you want the tool to poll for bandwidth usage.
While this tool may not offer as much granular information as other tools (e.g. bandwidth usage per application), it is a very good (and free!) tool for troubleshooting performance issues. It even offers the capability of setting thresholds for bandwidth e.g. give a warning notification when the bandwidth usage gets to a certain level. You can download this tool for free here.
FREE Real-Time Bandwidth Monitor Download (Direct Download Link):
2. Solarwinds NetFlow Traffic Analyzer
The NetFlow Traffic Analyzer (NTA) integrates with the Solarwinds Network Performance Monitor (NPM) and provides information about the bandwidth and traffic usage on a network at a very granular level. It is able to tell you the amount of bandwidth used by an IP address, application or protocol. It also has the ability to show the “Top Talkers” on a network which is very helpful for troubleshooting purposes. The Solarwinds NTA has reporting capabilities and can be used for Network Traffic Forensics (comb through data over several periods to discover issues).
You can try a fully functional Solarwinds Network Traffic Analyzer for 30 days after which you will require a license starting at $1875 for 100 elements. Keep in mind that since NTA requires Solarwinds NPM to function, you must also account for the separate license cost of the NPM.
Get Started Now FREE (Direct Download link):
http://www.solarwinds.com/register/registrationb.aspx?program=815&c=70150000000CgeI
3. PRTG Network Monitor
PRTG Network Monitor is a full blown, all-in-one monitoring solution with a lot of features including performance monitoring, server and application monitoring, virtual machine monitoring and also includes bandwidth monitoring.
To provide information about bandwidth and traffic usage, PRTG Network Monitor can use a variety of methods including SNMP, in-built Packet Sniffing and NetFlow. This information can be displayed in graphs and also exported in reports. We written up a thorough and exhaustive PRTG Review and Setup Guide for those who are interested in a more in-depth look.
PRTG Network Monitor is a Windows-based tool that comes in two editions: Freeware edition (for monitoring up to 100 sensors) and Commercial Edition (when you want to monitor more than 100 sensors) which starts at $1600 for 500 sensors.
Note: There is also a 30-day free trial that allows you to monitor unlimited sensors after which it falls back to default 100 sensor limit.
Official Download:
4. ManageEngine NetFlow Analyzer
ManageEngine's traffic analysis and monitoring tool for monitoring flow packets, including Netflow, Sflow, IPFix and others is a great choice finding and determining the cause of your bottlenecks. You can analyze bandwidth patterns per interface and drill down into which protocol, IP address and/or application is causing the issues with your network connection or network overhead.
On top of the basic functionality of traffic analysis and monitoring, you'll have the ability to create detailed reports and precisely estimate for future growth and bill as necessary if you are providing SLA's or ISP services.
Official Website: https://www.manageengine.com/products/netflow/
5. ntopng
My first experience with ntopng was with a client where I had to determine why Internet access was slow at certain times. The client was using pfSense as their edge device and ntopng was installed as a default package. Using ntopng, I was able to discover that one of the client’s servers had been hacked and was consuming so much bandwidth (probably being used as a streaming server) that the client was even maxing out the bandwidth provided by their ISP.
ntopng has a very simple web interface from which you can view network bandwidth/traffic usage information. ntopng can sort network traffic based on different options such as IP addresses, protocols, and ports. I especially like the “Top X talkers/listeners” feature provided by ntopng because it can let you know what device is currently hogging all the bandwidth on the network. ntopng also has reporting capability for what it monitors.
ntopng can be installed on both Unix and Windows operating systems. It comes in two editions: the Community edition which is free and the Professional edition which comes at a cost (149 Euros).
You can find more information about ntopng here.
6. Cacti
Cacti is an open-source network monitoring tool whose greatest strength lies in its graphing capability. It works by polling devices (mostly through SNMP) and presenting the polled data in graphs displayed through a web interface. Since it uses SNMP, one of the things you can graph is the network bandwidth usage on an interface, thereby making Cacti a valuable tool for Network Bandwidth Monitoring. If it doesn't suite your needs, you can find a Cacti Alternative here.
Cacti can be installed on either Unix or Windows OS and are available to download for free here.
7. BandwidthD
BandwidthD is another open-source solution for monitoring your traffic and network, but be aware, it has not been updated since 2013. Many admins are still using this software to understand which protocols and sources are using the highest amount of bandwidth in their networks.
You'll need to understand how to setup some manual configurations and it also requires some dependencies, including winpcap or libpcap (for linux/unix users) in order to collect data and such.
Overall though, its a free utility and has potential, although you should not expect any support of any kind with this software.
Official Site: http://bandwidthd.sourceforge.net
Conclusion
Being able to monitor bandwidth and traffic usage on a network can be very beneficial because you can use it to assess network performance issues, plan network capacity and also verify SLAs.
Looking at the tools we have discussed in this article, if you want to quickly set up a bandwidth monitoring tool, you may want to go for the Solarwinds Real-Time Bandwidth Monitor – It is by far the easiest and cheapest solution to get you started here and now.
If you are looking for a more robust solution that can give granular information, consider PRTG Network Monitor or Solarwinds NetFlow Traffic Analyzer (if cost is not a problem). If you are more interested in graphs, then Cacti may be the best tool to use.
We suggest your Grab the Latest FREE Version of Solarwinds Free Tool at NO-COST and get started Immediately.
Direct download Link can be found here: http://www.solarwinds.com/free-tools/real-time-bandwidth-monitor/registration?program=1643&campaign=70150000000PDzJ
