Colasoft Capsa 8 Free is a powerful tool for monitoring and analyzing network traffic, the free version of an enterprise package normally costing from $695.

The program has a vast and lengthy list of features, yet it’s also accessible to regular users. Just choosing an adapter and clicking “Start” gets you an attractive dashboard, with graphs showing network utilisation, traffic, and top traffic by protocol and domain (keep in mind that wifi devices can’t be monitored in the free edition).

That’s just the start. Click the Summary tab and you’ll see the data behind the charts, the total numbers of IP and MAC addresses used in this session, the various protocols, DNS queries and responses, SMTP/ POP3/ IMAP 4 connections and a whole lot more.

Maybe you want to zoom in? Choosing one of the Conversation tabs – TCP, say – allows you to drill down, see which packets went to/ from which addresses, the packet size, time sent, and more.

Capsa’s dashboard summarises your network traffic, and you can then zoom in on any detail

Colasoft Capsa 8 Free captures data packets, too, so you’re not restricted to summaries. Selecting any of these items displays the individual packets, and you can choose one, view any text it contains (maybe the password in a POP3 exchange, say). There’s even a detailed breakdown of the exchange, so for example you might view an IP packet to check its IP flags or TTL value.

This level of analysis isn’t just for a few internet standards, either. The program understands and can decode hundreds of protocols, and show you precisely what’s happening in every exchange.

Unsurprisingly, considering the full Enterprise version costs $995, the free build has a lot of restrictions. No monitoring of wifi devices, only one network adapter may be monitored, only one capture project can be run at a time, that’s limited to 4 hours maximum, only the first 10 private IP addresses will be analyzed, and so on.

Colasoft Capsa 8 Free has more than enough functionality left to make it interesting, though, for everyone from casual users to network experts. Give it a try.