Password Authentication Protocol


Password Authentication Protocol is a password-based authentication protocol used by Point to Point Protocol to validate users. Almost all network operating system remote servers support PAP. PAP is specified in.
PAP is considered a weak authentication scheme. Among PAP's deficiencies is the fact that it transmits unencrypted passwords over the network. PAP is therefore used only as a last resort when the remote server does not support a stronger scheme such as CHAP or EAP.

Working cycle

PAP authentication is only done at the time of the initial link establishment, and verifies the identity of the client using a two-way handshake.
  1. Client sends username and password. This is sent repeatedly until a response is received from the server.
  2. Server sends authentication-ack or authentication-nak

    PAP Packets

PAP packet embedded in a PPP frame. The protocol field has a value of
C023.
FlagAddressControlProtocol Payload FCSFlag