An External Enrollment Client Service is needed when an RA requests certification from a CA or when a CA requests a cross-certificate or a sub-CA certificate from an external CA. Every Certifier system that has at least one RA has to have an External Enrollment Client Service running on a Certifier Server instance.
The only settings that are needed with an External Enrollment Client Service are the Service description and the Status of the service (Active or Disabled).
Click the Continue button to accept changes made to the Service settings, or click Cancel to discard them. After clicking Continue, remember to Commit Changes on the Edit Server Entity page.