Assume the following scenario:

• A network device enrollment service (NDES) is implemented in the network.
• Requesting a certificate fails with the following error message:

The operation timed out 0x80072ee2 (WinHttp: 12002 ERROR_WINHTTP_TIMEOUT)

The Network Device Enrollment Service (NDES) provides a way for devices that do not have an identifier in Active Directory (for example, network devices such as routers, switches, printers, thin clients, or smartphones and tablets) to request certificates from a certification authority. For a more detailed description, see the article "Network Device Enrollment Service (NDES) Basics„.

In addition, the NDES server logs the following event:

The Network Device Enrollment Service cannot submit the certificate request (0x800706ba). The RPC server is unavailable.

A related event could also be:

The Network Device Enrollment Service cannot submit the certificate request (0x80010108). The object invoked has disconnected from its clients.

This error occurs when the NDES server cannot send the certificate request to the certificate authority. Possible causes can be:

• The certification authority is offline.
• The certificate authority is not reachable because a firewall prevents the connection. For the firewall rules to be set up, see the article "Required firewall rules for the Network Device Enrollment Service (NDES)„.

Related links:

• Requesting certificates via Network Device Enrollment Service (NDES) fails with error message "The public key does not meet the minimum size required by the specified certificate template. 0x80094811 (-2146875375 CERTSRV_E_KEY_LENGTH)".
• Overview of Windows events generated by the Network Device Enrollment Service (NDES).