Best 21 FREE Network Admin Tools for Everyday Troubleshooting!

Best Free Network Admins Tools and Software

by DAVID VARNUM, CCIE, VCP, MCSE+ - Last Updated: January 15, 2021

Every magician has a bag of tricks.

Every mechanic has a bag of tools.

Whether you’re designing a network, diagnosing an anomaly, troubleshooting an issue or monitoring an environment – your bag of Networking Tools and software should be complete, robust, and reliable.

This is why we’ve compiled a list of some of the Best Tools for Network administrators, at zero cost, to get you started.

Some will be familiar, some will be new.

Either way, this list should serve to either validate what you’re already using or supplement where you’re lacking.

Let’s dive in!

Here is our list of the twenty-one best network admin tools for everyday troubleshooting.

  1. SolarWinds Real-Time NetFlow Analyzer (FREE TOOL) A free network traffic analyzer that shows live traffic flows per user, device, address, or protocol. Installs on Windows Server.
  2. ManageEngine OpManager  (FREE TRIAL)A network, server, and endpoint monitoring system that is also able to manage the resource usage of hypervisors. Installs on Windows Server and Linux.
  3. Kiwi Syslog Server (Free) A Syslog message collector that can be upgraded to a more sophisticated paid version. Installs on Windows Server.
  4. Nagios An extensible, free network monitoring system, called Nagios Core with a paid version, called Nagios XI. Installs on Linux.
  5. Ntopng This is a free network traffic monitoring and analysis system. The software is free to use but the developers ask for a donation. Ntopng is available for Windows, Linux, macOS, Raspberry Pi, and Unix.
  6. SolarWinds TFTP Server A free, lightweight file transfer server for small network files. Installs on Windows Server.
  7. SolarWinds SFTP/SCP Server A free secure file transfer system that can manage multiple file movements from different devices simultaneously. Installs on Windows Server.
  8. Network Configuration Manager A system that automates the standardization of device configuration and then guards them against unauthorized changes. Installs on Windows Server.
  9. SolarWinds Port Scanner A free tool that identifies which IP addresses within a given range are in use and then checks all of the TCP and UDP ports on each. Installs on Windows Server.
  10. Wireshark / Tshark A free network packet sniffer that is highly respected and widely used. The packet viewer enables protocol identification.
  11. iPerf / JPerf A free tool that measures the available bandwidth between two nodes on a network. Installs on Windows, Linux, Android, macOS X, and Unix.
  12. Nmap / Zenmap A network monitoring system that generates a range of data including IP address usage. Nmap is a command-line system and Zenmap has a GUI interface. Installs on Windows, macOS, and Linux.
  13. Paessler SNMP Tester A free tool that checks on all of the conditions needed for SNMP agents to work properly and communicate with the SNMP manager. Installs on Windows Server.
  14. Angry IP Scanner A free tool that gathers IP address usage data. This utility offers a lightweight IP address manager and also a port scanner. Installs on Windows, macOS, and Linux.
  15. Ansible A task automation system that enables administrators to create playbooks, that act as workflows to complete mundane tasks. Runs on RHEL Linux.
  16. Netmiko A Python library that enables Python automation scripts to interact with network devices.
  17. Solar-PuTTY A free, secure terminal emulator that has an integrated secure file transfer utility. Runs on Windows Server.
  18. Notepad++ / UltraEdit / Sublime Text Three text editors that are great for editing scripts and config files.
  19. Cygwin Implements well-known Linux commands on PCs at the command line.
  20. A free, online diagramming tool that is great for creating ERDs and flow charts.
  21. SolarWinds Network Performance Monitor A masterful network monitoring system that gathers live statuses on network performance and traffic throughput from devices by SNMP communication methods. Runs on Windows Server.

Here’s the Best Network Admin Tools & Software of 2021:

Monitoring & Logging

SolarWinds Real-Time NetFlow Analyzer

“A real-time view of the network with SolarWinds NetFlow Analyzer”

When I need to troubleshoot network performance at a single site, or from a particular perspective, I rely on SolarWinds Real-Time NetFlow Analyzer. It’s free and simple to use.

Hours of finger-pointing can be eliminated by firing up this tool and looking at traffic going through a router or interface.

Easily identify users, apps, and devices that are consuming the most bandwidth.

netflow traffic analyzer

If you like the tool, I highly recommend upgrading it to the full version, which we covered in a previous article. It’s truly stellar.


ManageEngine OpManager

“An infrastructure monitor that covers network device and server statuses”

While many monitoring systems separate network performance monitoring and server monitoring out into two separate packages, OpManager combines the two in one purchase. This tool also covers some key applications, such as virtualizations.

OpManager uses a threshold system to identify when performance is likely to get impaired. There are many little problems that can soon stack up to bring performance to a level of impairment that users will notice. Catching these problems when they first arise gives you a chance to take action to head off disaster.

If a performance threshold gets crossed, the OpManager system generates an alert. This is shown in the service’s dashboard but it can also be forwarded to key personnel by SMS message or email.

ManageEngine OpManager

OpManager is available in a free version. This has all of the functionality of the paid edition, but it is limited to monitoring only three devices. Those interested in the paid version have three choices of plans: Standard, Professional, and Enterprise. All versions are available for installation on Windows Server and Linux.


Access a 30-day free trial of ManageEngine OpManager:

Kiwi Syslog Server (Free)

“View and archive Syslog messages and SNMP traps from five sources in real-time”

Again, if I’m troubleshooting a particular network, site or node, I rely on a logging mechanism to audit and aid in troubleshooting. With Kiwi Syslog Server Free Edition you can collect, view and archive up to 5 sources including routers, computers or other devices. Logs may also be written to disk—either in one large file or split up by day or priority.

It’s easy to use, and absolutely free for small, focused logging engagements. You can view logs in real-time, gather stats, and even setup warnings and alerts. It’s not just Syslog messages, but also SNMP traps you can collect and analyze with Kiwi.

If you want to get more serious, I recommend upgrading to the full version.

Top 17 FREE Tools for Network Administrators



Nagios is a networking monitoring software solution. In fact, it’s a suite of solutions for monitoring network availability, analyzing data flows and security, as well as collecting logs for auditing. It’s completely open source and has a vibrant community of like-minded developers and administrators.

With Nagios XI you can monitor everything from infrastructure to applications with granular detail. With Nagios Log Server, you can quickly sift through a central repository of audit logs, or setup triggers to alert you to critical events such as threats. And with Nagios Network Analyzer, dig deep into the health and integrity of your systems and network. Analyze flows, validate intent and troubleshoot with the lights on.

What I like most about Nagios is their straightforward approach to monitoring. They have multiple ways to represent data visually, which is another key interest of mine. Lastly, the built-in failover is wickedly cool if you start monitoring larger environments.

Top 17 FREE Tools for Network Administrators


“High-Speed Web-based Traffic Analysis and Flow Collection.”

Named after the popular top command in Unix, ntop shows network usage similarly to how top shows system usage. Ntopng, based on libpcap, is the next generation version of the original ntop. It was written in a portable manner, which gives it the flexibility to run on numerous platforms: Linux, Mac OSX, and Windows.

Web-based, ntopng allows you to view traffic data and gather reports regarding network status. You can use numerous criterion for sorting, including IP address, ports, Layer 7 protocols, BGP AS, and so on. You can even do long-term reports to collect metrics such as throughput over time.

I personally use this tool to generate detailed host-based reports showing applications latency, RTT, TCP statistics like retransmissions, out-of-orders, and zero windows.

Top 17 FREE Tools for Network Administrators

SolarWinds TFTP Server


At some point in your day-to-day as a network administrator, you’ll have to transfer a configuration file or image file to a router.

TFTP has been the easy go-to for this task for many years, and although alternative protocols are out there, good chances are you’ll still run into the case where TFTP is just easier.

This is the reason why I always have a TFTP server app loaded on my laptop.

My personal choice for this software is SolarWinds TFTP Server.

We’ve written about it in the past and it still holds its rank. It’s a multi-threaded, reliable and works like a champ. Best of all, it’s free.

As a bonus little feature, you can actually authorize specific IPs or ranges to limit sending and receiving directly to the server for advanced security.

And if you’re doing this regularly or from a central server, run it as a service for 24×7 availability.


SolarWinds SFTP/SCP Server

SFTP Server

Those alternative protocols I mentioned before? SFTP and SCP are two of them.

If you have the capability to use the secure protocols instead of TFTP, do it, just make sure you have trusted software like SolarWinds SFTP/SCP Server.

Like the TFTP Server software, SolarWinds SFTP/SCP Server is multi-threaded and commonly used to upload and download executable images and back-up configurations for routers and switches.

You can authorize specific IPs or ranges to limit sending and receiving directly to the server for advanced security, and run it as a service on a centralized server.


Network Configuration Manager

Network Configuration Management Tool

Assuming you need one of these tools, it’s likely you’re transferring config or images files to/from network devices.

If you’ve never checked it out, I highly recommend giving SolarWinds Network Configuration Manager a whirl.

It’s Free to try but does have a cost associated past the trial period.

I am intimately familiar with several very large networks that use SolarWinds NCM for configuration, compliance and image transfers. In my opinion, it’s absolutely worth every penny.



Port & IP Scanner (GUI & Command-line)

portscanner gui

Scan available IP Addresses and ranges, along with TCP and UDP ports of your networking devices, servers and desktops!

This tool works much like other port scanners, but with some added features that really set it apart from almost any other tool we’ve worked with.

This tool can be run either from the GUI or via command-line if needed and it gives insights into TCP/UDP port statuses, Resolves hosts names, MAC Addresses and even OS fingerprinting.

portscanner command-line

Some Features & capabilities include:

  • Save Scan configurations for Future scans
  • Define DNS Server for scanning
  • Either GUI or Command-line based scanning
  • Multi-Threaded Post scans!
  • and many more features!


Wireshark / Tshark

This is a no-brainer for most but needs to be mentioned for integrity’s sake.

Wireshark is an unparalleled network protocol analyzer, and honestly, one of the best free network tools ever made.

When you’re troubleshooting an issue and actually need to get into the weeds to find out what’s going on – this is your microscope. Never leave home without it!

If you’re looking for some command-line capturing, or maybe you want to programmatically trigger packet captures, don’t forget to check out TShark. It’s included with Wireshark, and totally awesome.

Top 17 FREE Tools for Network Administrators


iPerf / JPerf

Between any two nodes is a network – be it vast or small.

A simple ping between the two nodes is only good for general reachability and understanding the round-trip time for the small packets.

If you want to measure actually achievable bandwidth, you need another tool such as iPerf.

iPerf3 is the latest iteration of this tool. You run the client on two ends of a network, configuring the parameters needed to measure performance. It supports tuning of many parameters related to timing, buffers, and protocols (TCP, UDP, SCTP with IPv4 and IPv6). Upon execution, it actively measures and reports on bandwidth, loss, latency, jitter, and so on. You can initiate multiple simultaneous connections to truly simulate load across the network. Very handy tool!

If you’re more of a GUI person, check out Jperf. It’s up there in age but still works like a champ.

Top 17 FREE Tools for Network Administrators

Nmap / Zenmap

I personally use Nmap at least once a week. Almost verbatim from their website: Nmap (Network Mapper) is a security scanner used to discover hosts and services on a computer network, thus creating a “map” of the network. To accomplish its goal, Nmap sends specially crafted packets to the target host and then analyzes the responses.

Nmap provides an incredible number of features for probing networks, including host discovery, service discovery and operating system detection. These features are extensible by scripts that provide more advanced service detection, vulnerability detection, and other features. In fact, Nmap is used in the backend for various security assessment tools such as Nexpose.

Again, if you’re more a fan of GUIs, make sure the download the bundle with Zenmap.

Top 17 FREE Tools for Network Administrators

Paessler SNMP Tester

SNMP can be hard. This is why you need a good tester. There are a few out there, but I’ve found great success with Paessler’s SNMP tester.

The idea of this program is to have a tool that enables the user to debug SNMP activities in order to find communication and/or data problems in SNMP monitoring configurations. Are your devices configured properly? Are you using the correct keys? Use this tool to validate if your SNMP configuration will function with programs like PRTG Network Monitor.

Top 17 FREE Tools for Network Administrators


Angry IP Scanner

Angry IP scanner is an open-source, multi-threaded IP address and port scanner. Similar to Nmap, and used by millions, it’s become a standard tool for network admins. Angry IP Scanner first rapidly pings, then checks port status, then starts resolving hostnames, gathering MAC addresses, OSs and whatever it can discern based on the data gathered. It can collect NetBIOS info like workgroup and domain names, as well as logged-in users if you happen to have to privileged rights to retrieve this information. Like Nmap, it’s extensible with plugins. Scanning results can be saved to CSV, TXT, XML or IP-Port list files.

Runs on Windows, Mac, and Linux. Get it here.

Top 17 FREE Tools for Network Administrators



Configuration & Transfers


“No one likes repetitive tasks.”

Ansible is a simple and powerful automation engine with the goal of reducing repetition by automating tasks. It’s vendor agnostic, programmable and relatively easy to learn. The folks at Ansible believe that automation shouldn’t be more complex than the tasks it’s replacing.

From a network perspective, I like this tool for generating configuration files based on my custom templates. I can quickly build “playbooks” for a large number of scenarios, ensuring that my configuration files are properly built based upon my standards and that my network devices are configured accordingly.

If you want to get more with a GUI, check out Ansible Tower. Super clean.

Top 17 FREE Tools for Network Administrators


Created by Kirk Byers, Netmiko is a multi-vendor Python library that simplifies Paramiko, gearing it toward network devices. This is a more advanced tool, and only beneficial if you’re using Python for scripting or automation. It simplifies SSH connections, command execution and data retrieval like no-one’s business.

Each vendor has their own quirks regarding shell interaction. Whether is privileged modes, expert modes or commit functions, Netmiko is designed to simplify this lower-level SSH management across a wide set of networking vendors.

Netmiko current supports the following platforms:

  • Cisco IOS, IOS-XE, IOS-XR, ASA, NX-OS, and WLC (with limited testing)
  • Arista EOS
  • HP ProCurve
  • HP Comware (limited testing)
  • Juniper Junos
  • Brocade VDX (limited testing)
  • F5 LTM (experimental)
  • Huawei (limited testing)

Top 17 FREE Tools for Network Administrators


Terminals & Text Editors


Solar-PuTTy is a Advanced PuTTY Alternative the gives you extra features that the normally do not come with the standard putty!

Features include:

  • SCP, SSH, Telnet & SFTP connections
  • Save Credentials w/ Private Keys for Auto logins
  • Tabbed Interface for multiple sessions at the same time!
  • Auto Reconnect of Lost sessions
  • Favorite your most Frequently Used Sessions in a Sidebar Panel
  • File Transfer Capabilities (via SFTP)
  • Post Connection Script Support & Execution
  • Integrate with Windows Search!

Download and Use 100% Free for LIFE:

Solar-PuTTY Download

Notepad++ / UltraEdit / Sublime Text

If you’re still using regular old Notepad, you have no idea what you’re missing out on. Step up your text game with one of these text editors. I guarantee you will not regret it!

We use Notepad++ Every single day – whether we’re editing PHP files, Nagios Configs, or Searching through Multiple files for a string or Text at the same time, Notepad++ is the best text-editor on the market!


If you’ve ever used Linux, you’ve become familiar with useful commands such as ‘grep’, ‘ls’, ‘top’, ‘df’, ‘pwd’ and so on. In the Windows world, we are missing some of these commands, and we have them, it’s written in some other non-intuitive syntax.   Wouldn’t it be great to have Linux commands and applets in Window? Enter Cygwin.

Cygwin is a large collection of GNU and Open Source tools, which provide functionality similar to a Linux distribution on Windows. Not only can you run familiar commands, but also you can load (similar to apt-get or yum) various Linux tools. Some favorites of mine are wget and curl. If I’m running Windows, I’m running Cygwin.

Top 17 FREE Tools for Network Administrators

I love Visio. It’s undoubtedly the best tool for designing network diagrams. However, it can be expensive, and it only runs on Windows. As a Mac user, I run a Windows VM just so I can use Microsoft Visio. While this does function, I’ve recently started using, a browser-based diagramming application. It’s awesome!

Whether you’re building an engineering diagram or a network diagram, has tons of templates to get you started. It connects to online storage environments like Dropbox and Google Drive for real-time saving. No more losing data. Again, it’s absolutely free, and something you can rely on for cloud-based diagrams that are shareable and exportable.

Top 17 FREE Tools for Network Administrators



SolarWinds Orion Network Performance Monitor (NPM)

Say your tool-bag is full, and now you’re ready to upgrade to a professional set.

For enterprise networks, you need robust monitoring, advanced troubleshooting, historical analytics, system analysis, fault alerting, capacity forecasting, detailed reporting, and a constant finger on the pulse of your infrastructure.

This is where SolarWinds Orion Network Performance Monitor (NPM) steps in.

Winner of our recent Network Manager Software Smackdown, SolarWinds NPM is earned this achievement through constant innovation, easy-to-use interfaces, wide user adoption and an unmatched community in the performance and monitoring industries.

If you need more reasons to check out SolarWinds NPM, read our articles highlighting a few of the new advancements released in their latest iteration of the platform – version 12. NetPath, in particular, is a mind-blowing addition to this toolset that you won’t get anywhere else.

Top 17 FREE Tools for Network Administrators

Get started with a free trial and start managing your network like a boss. And don’t forget to check out our 2020 Network Monitoring Software smackdown!