Cause—On Forefront UAG activation, a timeout occurred and the 6to4 interface could not be enabled.

Warning: Serious problems may occur if you modify the registry incorrectly using the Registry Editor or another method. These problems may require that you reinstall your operating system. Modify the registry at your own risk.

Solution 1— Ensure that IPv6 components are fully enabled as follows:

1. At an elevated command prompt, type reg query HKLM\SYSTEM\CurrentControlSet\Services\tcpip6\Parameters /v DisabledComponents.
   If the DisabledComponents registry value is not present, the command displays ERROR: The system was unable to find the specified registry key or value. In such a case, IPv6 components are enabled.
2. If the DisabledComponents registry value is present, the command displays its value. If DisabledComponents is present and it is not 0, change it to 0.
3. Restart the Forefront UAG server.
4. At an elevated command prompt, type netsh int ipv6 6to4 show state. The output should show that the 6to4 interface is Enabled and has the 1st external IPv4 address.
5. Reactivate Forefront UAG.

Solution 2— Manually enable the 6to4 network interface as follows:

1. At an elevated command prompt, type netsh int 6to4 set state enabled.
2. Type netsh int ipv6 6to4 show state. The output should show that the 6to4 interface is Enabled.
3. Reactivate Forefront UAG.
4. If the 6to4 interface is still disabled, use the resulting error message to troubleshoot the problem further.

Solution 3—Ensure that public IPv4 addresses are configured on the external-facing adapter (Using private IP ranges like 10.0.0.0 or 192.168.0.0 on the external adapter is not supported), and then reactivate Forefront UAG.