Wireshark (formerly known as Ethereal until a few years ago) is a very popular, completely free and highly recommended network protocol analyzer. It can view data in real-time and also log the data being sent on a network to a file on disk. With Wireshark, you can perform real-time and interactive analysis of the data that has been captured, perfect for diagnosis errors on a network.
Some of the powerful features available with Wireshark include the ability to view the (reconstructed) stream of a TCP/UDP session while supportng literally hundreds of different types of data and media.
A separate program is also include called tshark. For those familiar, tshark is Wireshark's equivalent of tcpdump which is traditionally a console-only version of Wireshark.
Called by some the Swiss army knife of network troubleshooting, is it by far one of the best Network sniffers available on the market and the very best among free applications.
Wireshark traces its roots back to 1998, so tons of development steps and progress has been made since then!Wireshark 1.12.3
is licensed as Freeware
for the Windows operating system / platform without restrictions. Wireshark is available to all software users as a free download (Freeware).
Wireshark Virus and Malware Tests:
For security reasons, you should also check out the Wireshark virus and malware test
that has been uploaded; additional Wireshark screenshots may be available, too.