TCPSniffer

TCPSniffer is a simple-to-use application that facilitates a packet analyzer which you can use to intercept network traffic to find out all connections established between your computer and others.

No setup necessary, besides .NET Framework

The tool's wrapped in a single .exe file that can be saved in any part of the disk or copied to a removable storage unit, in order to launch it on any computer with minimum effort. However, you should keep in mind that you must have .NET Framework installed. It doesn't make any changes in the Windows registry.

Scan the local network and examine hosts

When it comes to the interface, TCPSniffer adopts a normal window with a neatly organized layout, where you can perform a scan in the local network by specifying the local IP address, along with the connection IP address and port number.
The scanner gets triggered with one click, after which the software utility analyzes all packets sent in the network and displays the source and destination IP addresses and port numbers, along with the host name and status of each identified entry.

Evaluation and observations

Unfortunately, it doesn't implement buttons for copying data to the Clipboard, printing it, or exporting it to file. On the other hand, you can select a cell to copy contents with the Ctrl+C key combination.
Furthermore, it doesn't integrate options for monitoring network traffic to automatically capture log details to file, which would've come in handy for minimizing the program to carry on with your usual PC activity and later investigate the logs.

Conclusion

CPU and RAM usage was minimal, and we haven't come across any stability issues, since TCPSniffer didn't hang, crash or show errors. All in all, this tool offers a straightforward solution for analyzing network traffic.