IPv6 Command Line Utility - Netsh.exe

All IPv6 connections have been set up. Router checked, switches checked; and nothing. No traffic.

Well, all Windows OS's since Windows 2003 have a utility, namely Netsh.exe,  that will help you drill down on a suspected IPv6 problem.

You run Netsh.exe from the command prompt, or interactively from a Netsh prompt. Of course, you can create a script file too. Search for "netsh overview" in Windows Help and Support. 

Netsh interface ipv6

IPv6 was designed to be self-configuring. In those cases where the role of the computer needs special connectivity, you need to set additional IPv6 parameters. This command will get you started. All common configurations for address and routes are discovered through router discovery. If your computer / server acts as a router, you need to set all addresses manually through this command.

Everyday commands that lets you configure an IPv6 connection include:

Netsh interface ipv6 show interface	displays the list of IPv6 interfaces
Netsh interface ipv6 show address	displays the list of IPv6 addresses for each interface
Netsh interface ipv6 show routes	displays the list of IPv6 routes in the IPv6 routing table. To see all the IPv6 routes, use the Netsh interface ipv6 show routes level = verbose command.
Netsh interface ipv6 show neighbors	displays the contents of the neighbor cache
Netsh interface ipv6 show destinationcache	displays the contents of the destination cache
Netsh interface ipv6 6to4	display the configuration of the 6to4 component on either a 6to4 host or a 6to4 router
Netsh interface ipv6 isatap	used to configure PortProxy behavior or to display its configuration
Netsh interface portproxy	used to configure PortProxy behavior or to display its configuration