Version 5 Manual

Raw TCP sockets and Npcap

Note: the information in this section is specific to the Windows version of PingPlotter.

TCP traceroute allows access to some targets that were not previously available, but this comes with some caveats.

One challenge that many users will face is that most operating systems today (all Windows versions XP or newer) block the ability to create TCP packets with the options needed for traceroute. See a Microsoft white paper for some more details on this.

The best way to get around this problem is to use a custom network driver. PingPlotter supports the use of Npcap (and is compatible with now-depreciated WinPcap) for this.

A note about Npcap

While PingPloter can use Npcap to generate TCP packets, it is a third-party framework and may be made incompatible through future updates. If you encounter compatibility issues with Npcap, please reach out to our Service Team.

How to install the driver

Install steps:

  • Visit the Npcap site, then download and run the installer.
  • Use the TCP packet type in PingPlotter.
  • You're done!

Shortcomings with Npcap and PingPlotter

Npcap allows PingPlotter to send packets directly to the network card. This is very powerful, but also means that the Windows protocol stacks don't help us with routing or validation of the packet. PingPlotter should do a good job with detecting if a gateway should be used and sending to that gateway, but might not work correctly with multiple gateways, or other complicated network setups. Please contact us if you find a network environment where PingPlotter seems to be making poor decisions or causing problems.

If you're not running as administrator (or using PingPlotter as a service), then you'll need to configure Npcap to start automatically (which is its default install mode). For more details on how to do this, see the Npcap FAQ.