PAP Authentication Protocol Password Authentication Protocol (PAP) is a very basic two-way process. The username and password are sent in plain text, there is no encryption or protection. If it is accepted, the connection is allowed. PAP is not interactive in anyway, PAP is not considered a strong authentication protocol. When the ppp authentication pap command is used, the username and password are sent as one LCP data package, rather than the server sending a login prompt and waiting for a response. Although, PAP cannot be said to be a very strong authentication protocol but, there are times when using PAP can be justified. PAP may be used in the following situations: i. When an installed network applications does not support CHAP ii. Incompatibilities between different vendor implementations of CHAP iii. Circumstances where a plaintext password must be available to simulate a login at the remote host How to configure PAP on a Cisco router interface The process outlined below d...