Internet Storm Center

I received a couple of questions regarding Wireshark and Npcap.

First of all, it's not a requirement to install Npcap if you want to upgrade to Wireshark 3.

You can just deselect the toggle to install Npcap:

And then Wireshark 3 will use WinPcap (installed with prior versions of Wireshark).

If you go to Help / About Wireshark, you can see what capture library is currently used by Wireshark on Windows:

Actually, you don't even have to install a packet capture library on the Windows machine you install Wireshark on, as long as you don't have to capture packets with Wireshark on that machine.

WinPcap is no longer maintained, and that is reflected in the version that comes bundled with Wireshark 2:

It dates from 2013.

Johannes also remarked that the Npcap license allows free use of Npcap on up to 5 Windows machines. If you have more in your organisation, you need to obtain a commercial license:

The standard version is also limited to installation on five systems.

However, there is an exception for Wireshark (and Nmap)

Copies of Npcap do not count toward the five copy, five computer, or five user limitations imposed by this section if they are installed and used solely in conjunction with any of the following software:

o The Nmap Security Scanner, as distributed from https://nmap.org

o The Wireshark network protocol analyzer, as distributed from https://www.wireshark.org/

If you install Wireshark with Npcap, and you use Npcap exclusively with Wireshark and/or Nmap, then the standard license still applies even with more than 5 machines.

Didier Stevens
Senior handler
Microsoft MVP
blog.DidierStevens.com DidierStevensLabs.com