Mastering Active Directory - Second Edition

Online Responder

Online Responder is responsible for producing information about certificate status. When I talked about Certification Authority Web Enrollment, I explained how the CRL includes the entire list of certificates that are expired or have been revoked within the PKI. The list will keep growing based on the number of certificates it manages.

Instead of using bulk data, Online Responder will respond to individual requests from users to verify the status of a particular certificate. This is more efficient than the CRL method as the request is focused on finding out the status of a certificate at a given time.