On a computer on which you have DirectAccess clients configured to use Teredo tunneling, you upgrade the operating system to Windows 10, version 1803 and later versions of Windows 10. After the upgrade, the DirectAccess clients cannot connect.
At this point, if you run netsh interface teredo, the command returns a message that states that Teredo tunneling is disabled.
This issue occurs because Teredo tunneling is disabled by default in Windows 10, version 1803 and later versions of Windows 10.
How to avoid this issue
Before you upgrade the system to Windows 10, make sure that Teredo tunneling is enabled by using Group Policy.
To do this, browse to the following policy in Group Policy:
Computer Configuration > Policies > Administrative Templates > Network > TCPIP Settings > IPV6 Transition Technologies > Set Teredo State
Then, set the states to Client or Enterprise Client.
How to fix this issue
If you already experience this issue, use one of the following methods to fix it.
- Run the following command on each DA clients to enable Teredo tunneling:
netsh interface teredo set state Enterprise
- Configure the Set Teredo State Group Policy that is mentioned under "How to avoid this issue" to enable Teredo tunneling.
Note If you have to connect to the internal resource remotely to configure the policy, use IPHTTPS to connect to the DirectAccess Server or use VPN.