If we're looking for an application with which we can analyze our local network, without generating traffic, we can choose to use NetworkMiner, a forensic network analysis tool, that will allow us to detect a lot of information about the computers that are part of our network.
A watchdog for your network
This kind of tool is usually used to keep an eye on a network of which we are the administrator with the objective of detecting failures or the misuse of it, as well as checking if data have been added or eliminated without permission, being an application that is indicated for company use.
The program has an interface based on tabs, that favors its use, because each one of them will show us different information about each connection and each computer, making it as simple as possible to obtain all the information that we're looking for.
The application detects the user names and keys that have been inputted, it will intercept images to check that there is nothing illegal in them, and it is capable of letting us know if the keywords that we have indicated are inputted, thus avoiding the misuse of the computers of our office.