Troubleshooting Teredo

First, determine the current Teredo configuration by running the following command:

netsh interface teredo show state

If the output includes the message, “Error: client is in a managed network,” Teredo is configured as a standard client, which does not function when connected to a domain controller. To resolve this, run the following command:

netsh interface ipv6 set teredo enterpriseclient

If Teredo still does not work, it’s likely that your network infrastructure blocks the IPv4 UDP traffic that Teredo uses for communications. Work with your network administrators to ensure that routers and firewalls allow incoming UDP traffic.

You can enable tracing to troubleshoot more complex problems by following these steps:

1. Set the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\IpHl pSvc\Enable- FileTracing registry key to 1.

2. Stop the IP Helper service by running the command net stop iphlpsvc.

3. Delete the contents of the %SystemRoot%\Tracing folder.

4. Start the IP Helper service by running the command net start iphlpsvc.

5. Reproduce the problem. For example, you can force Teredo to attempt a connection by running the command netsh interface teredo show state.

Now you can examine the trace logs in the %SystemRoot%\Tracing folder or submit the logs to technical support.

6. Set the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\IpHl pSvc\Enable- FileTracing registry key to 0.

7. Stop the IP Helper service by running the command net stop iphlpsvc, and then restart it by running the command net start iphlpsvc.