Top 10 TCP/IP tools every networking pro should know

Any craftsman needs tools to get the job done, and so do network engineers. Whether the task is to build, test, monitor or troubleshoot, network engineers need tools and network utilities to help them do their jobs well. However, much like your local hardware store, there are a dizzying amount of tools and utilities that are available for networks today.

TCP/IP utilities are essential—not only will they help you on your networking exams, but you'll also be able to diagnose most TCP/IP problems and begin working on solutions. So, which ones should be in every network engineer’s toolbox? Let’s look at the top 10.

1.     Wireshark (free, open source)

The root cause of most network performance and security problems can be found in the packet detail traversing the network. Wireshark is the industry standard tool to collect and interpret this traffic, with almost one million downloads every month.

Wireshark enables engineers to quickly get to the packet level of a problem. This allows them to quickly determine if the issue is due to the network, server, service or client. Rather than guess at the cause of an issue, they can utilize Wireshark to see the real truth.  

At times, however, the packet output can be a challenge to read, especially for those new to traffic analysis. At Pluralsight, we have developed several courses around this essential analyzer, including the Foundational TCP Analysis with Wireshark course, which provides a deep dive into how to use Wireshark for troubleshooting complex TCP issues.

2.     Nmap (free, open source)

Maintaining security is critical on networks today, and it doesn’t happen by accident. Networks need to be scanned and monitored persistently for unauthorized devices and open ports, enabling engineers to stay ahead of intrusions and vulnerabilities that potential hackers could compromise.

Nmap provides utilities to determine what hosts are available on the network, what ports are available on those hosts, what OS and firewalls are in use and much more. It has the capability to scan whole subnets and TCP port ranges, allowing engineers to spot problem devices and open sockets.

3.     iPerf3 (free, open source)

An important step to troubleshooting any network problem is validating throughput and packet loss from end to end. Just because a connection or circuit is advertised at 1Gbps does not mean that we are actually achieving that amount of bandwidth.

iPerf3 is a tool that enables engineers to measure network throughput, packet loss and jitter. If traffic congestion or link-level errors are causing packet loss, or if latency has shifted affecting throughput, iPerf3 can help in isolating and resolving these issues. These measurements help to pinpoint whether the network is causing the performance problem or not.

4.     Cisco Packet Tracer (free)

Network simulation, especially in the design stage, is a must for any network engineer. Cisco designed the Packet Tracer tool to help engineers simulate and test network environments before they are rolled out to the enterprise.

These tools are especially helpful when preparing for industry certification exams, as large environments can be built and tested without the need for expensive hardware.

5.     Putty (free, open-source)

Putty is everywhere, even after two full decades of use. For many engineers, Putty is like a right hand, enabling them to access and configure network devices. Although automation is becoming king—and fancy new automation tools are entering the market, engineers still need direct access to the infrastructure for basic setup and troubleshooting. For most people, Putty is still the go-to tool for command line access.

6.     Netstat (free, command line, multiple operating systems)

What TCP or UDP sockets are in use on a given system? What servers is a machine connecting to and on what ports? What is the TCP state of the connection?

Netstat (Network Statistics) is a command-line tool available on most operating systems that will display the current status of TCP and UDP conversations. This data is very helpful when tracking down server load, mapping connections to a specific process or monitoring the security of a system that is under attack.

7.     Angry IP Scanner (free, open-source)

While similar to Nmap, the Angry IP Scanner adds both speed and ease to the equation. The tool simply pings each IP address in the configuration list to determine if the device is alive, and then it optionally can resolve the hostname, discover the MAC address and perform a port scan. The results of these scans can be exported to excel or several other output formats.

A quick network ping scan is important for any network engineer to have in the toolbox.

8.     PingPlotter (Free to try, $39 to buy)

This tool combines ping, traceroute and long-term graphing to persistently monitor a network path for health, latency and loss. It’s a great tool to have on hand for connections that drop intermittently, whether at home or in the office. If a connection does intermittently drop, PingPlotter can quickly pinpoint the exact hop along the path at fault, which saves a lot of time when troubleshooting. 

While this is a paid tool, available by either a perpetual license or subscription, it is a fantastic way to isolate problem points along a network path.

9.     cURL (free, command-line, open-source)

The cURL utility allows network engineers to query URLs from the command line. If mobile device applications, IoT devices or other APIs are having connectivity issues, the cURL utility can help to test authentication, certificates, and GET and POST methods to help troubleshoot the cause of the problem.

After all, we know that most people are going to blame the network anyway. Network engineers need an application level tool in the toolbox to put the blame in the right place.

10.  PRTG WiFi Monitor (free for up to 100 sensors)

This list would not be complete without at least one wireless tool.

Every network engineer has to cope with WiFi at some point. Most of them don’t need the full-blown capability of a complex spectrum analyzer. Usually, they just need to know what access points, networks, signal strength and channels are available at a given spot. To find this out, a tool like PRTG WiFi is a great place to start.

This tool shows channel usage, SSID availability, signal strength, noise and more. It fits in well when network engineers need to troubleshoot problems with the final hop.

These top 10 tools are great for network analysis and troubleshooting and should be a part of every engineer’s toolbox. They help with most of the issues that engineers face today and can go a long way in resolving network problems quickly.