s! type = PAP|MD5CHAP|MSCHAPv2|EAP|CERT Selects the types of authentication which this Remote Access server will attempt ...

%1!s! [type = ] PAP|MD5CHAP|MSCHAPv2|EAP|CERT                   
                                                                       
Selects the types of authentication which this Remote Access server    
will attempt to negotiate.  Negotiation will be in the order           
most-secure to least-secure.  Once both client and server agree upon an
authentication type, the PPP negotiation will follow the appropriate   
RFCs.                                                                  
                                                                       
   type - the type                                                     
     PAP      - Password Authentication Protocol (clear text).         
     MD5CHAP  - Challenge Handshake Authentication Protocol using      
                Message Digest 5 hashing scheme to encrypt the response.
     MSCHAPv2 - Version 2 of MSCHAP.                                   
     EAP      - Extensible Authentication Protocol.                    
     CERT     - Certificate Authentication for IKEv2.