Analysis of information sources in references of the Wikipedia article "Extensible Authentication Protocol" in English language version.
The certificate_request message is included when the server desires the peer to authenticate itself via public key. While the EAP server SHOULD require peer authentication, this is not mandatory, since there are circumstances in which peer authentication will not be needed (e.g., emergency services, as described in [UNAUTH]), or where the peer will authenticate via some other means.
The certificate_request message is included when the server desires the peer to authenticate itself via public key. While the EAP server SHOULD require peer authentication, this is not mandatory, since there are circumstances in which peer authentication will not be needed (e.g., emergency services, as described in [UNAUTH]), or where the peer will authenticate via some other means.