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10 Free Network Management Tools

  • Throughout my 15+ year career as a network engineer, I've evaluated, implemented and used plenty of open source networking tools in a variety of environments. Some ended up being too buggy, lacked critical features or were too time consuming to maintain in production. Others proved to be a great fit and I've relied on  them a great deal. In this slideshow, I'll discuss 10 free networking tools that I believe are incredibly useful when it comes to day-to-day management and troubleshooting of enterprise networks.

    Some IT pros completely disregard free open source tools because they feel they are far inferior when compared to commercial products that perform similar duties. While many proprietary products have added features and extra polish that make using and maintaining them easier, open source tools often are a satisfactory alternative. So if open source tools are "good enough" and free, they should never be overlooked or omitted from consideration.

    When looking for free open source networking tools that can be viable options for production use, look first at established tools that maintain active development communities. While new open source solutions may offer new and advanced features, they're less likely to be production ready. A few solutions on this list have been around for nearly two decades, yet still are considered some of the best tools available. Open source projects can be slow to develop, so you may find that some tools have great promise, but aren't yet ready for prime time. In situations like these, your only alternative might be to purchase a proprietary vendor solution.

    In addition to this list, there are complementary open source tools that don't necessarily perform any specific network functions, but can help with the network management process. For example, tools such as dig and Nmap are fantastic for information gathering and basic troubleshooting, and should be part of any network engineers’ toolset. Other essential tools include  KeePass, PuTTY and WinMerge.

    Continue on to learn about 10 free tools that provide a range of network management and troubleshooting functions for a variety of network infrastructure scenarios.

  • Nagios Core

    One of the key responsibilities of any network administrator is to monitor the network and fix issues that cause outages as quickly as possible. Nagios Core is used worldwide to help monitor networks and track various infrastructure problems. Nagios Core uses a highly scalable architecture focused on performing diagnostic checks, issuing alerts when these checks fail, and ultimately, ensuring admins acknowledge issues and resolve them.



    As networks expand, it can become difficult to manage public and private IPv4 and/or IPv6 space you have allocated. There are plenty of IP address management (IPAM) tools on the market, including several that are open source. One of the better free choices is NIPAP. This suite of tools is fairly easy to set up and includes features such as search capabilities, address usage statistics, and the ability to manage it via command line or through a web GUI. It also has some decent documentation to help get you up and running. So if you’re in a situation where your IP address management has outgrown that old spreadsheet you’re currently using, you will definitely want to check out NIPAP.

  • Wireshark

    Easily one of the most useful troubleshooting tools around is Wireshark. The packet capture software is used to collect and analyze packets as they flow in, out and through a network. Packets can then be analyzed to help diagnose issues such as application latency, security policies, and routing problems. Despite Wireshark being open source, it's widely used by network support technicians in companies both small and large.

  • Ntopng Community

    What used to be known as Ntop is now called Ntopng, the next generation of flow collection tools. The Ntopng Community edition can be setup as an analyzer as well as a probe. That means you’ll have to place the Ntopng instance in a strategic location so the traffic you want to analyze passes by the Ntopng server. A more practical solution is to deploy Ntopng probes to collect flow data from the device itself.

    But be aware, the Ntopng probes -- known as nProbes are not open source and each one will cost you about $170, depending on if you need to add any of the available probe plugins. While it’s too bad that there is no way to harness the full power of Ntopng Community without paying for one or more nProbes, it's still a great low-cost tool.

  • pfSense

    pfSense is a popular open source firewall in the enterprise. Hardware requirements are minimal – you can build your own firewall using x86 or x86 hardware, or purchase dedicated hardware. You also have the option of running pfSense as a virtual appliance either in your own data center or in the cloud. Features include almost everything you would expect from a commercial product, including stateful tables, VPN functionality, and integration with other open source tools including Ntopng and Snort.

  • Cacti

    The Simple Network Management Protocol (SNMP) remains the go-to method for monitoring everything from device and interface ups/downs to bandwidth/CPU utilization and even hardware appliance temperature statistics. Cacti is one of the most popular open source tools that puts all these capabilities and more into one complete package. Cacti, which originally went by the name MRTG, is a set of graphical front-end software components that use an industry standard data collection tool called RRDtool. Cacti improved on MRTG with simplified installation and setup procedures. The Cacti suite is commonly deployed to poll various network components in order to collect and graph SNMP data to create historical graphs.

  • Zen Load Balancer Community Edition

    When you need basic server load-balancing capabilities, but don’t have a budget, the Zen Load Balancer is a mature enough free and open solution to meet most of your needs. Since the community edition is downloaded as an ISO image, you can easily spin it up in any number of on-premises or cloud-based virtual machine instances. Once installed, you simply login to a web GUI, configure your virtual server IP addresses and farms, and determine the load balancing methodology. While this free version doesn’t have any of the bells and whistles that many commercial versions tout, it handles basic layer 3 load balancing just fine.

  • Graylog

    Log management tools may not be the most exciting software around, but they are often the most valuable. Graylog is a wonderful open source choice to use as your company’s centralized log server. With it, you can collect syslog messages and even Windows events by using third-party add-ons. Once you begin collecting data, you can search, analyze and parse messages for network troubleshooting and root-cause analysis. The free tool also is great for triggering and alerting on specific messages that may indicate network problems that should be investigated. The interface is easy to use and highly intuitive for most network administrators. In fact, it’s so good in fact that it almost makes log management fun.

  • Scalr

    For those of you that are either working in or exploring hybrid clouds, one tool that you absolutely need to check out is Scalr. While there are plenty of fantastic and innovative commercial cloud management platforms available, Scalr is a solid open source option. The platform automates and streamlines standardized network and security policies throughout both private and public clouds. While Scalr is available in paid SaaS and on-premises versions, there is an open source version that many midsize and enterprise-class organizations are using in production today.