Windows 10 version 1803 and later disable Teredo by default, so we need to enable it in order to get IPv6 behind NAT using Teredo.

1. Choose Teredo server here.
2. Open an elevated command prompt.
3. Type netsh interface teredo show state to show the status of Teredo tunnel.
4. Type netsh interface teredo set state client example.com replacing example.com with your chosen Teredo server.
5. Type netsh interface teredo show state to show the status of Teredo tunnel.
   1. If state says offline and error says “client is in a managed network”, type netsh interface teredo set state enterpriseclient.
   2. If state says dormant, Teredo has been enabled.
6. Try to ping an IPv6 server or use test-ipv6.com.
7. Type netsh interface teredo show state to show the status of Teredo tunnel. If state says qualified, then your Teredo tunnel is working.