Cayman Systems 2E-H-W User Manual page 146

How Your Cayman 2E-H-W Works
C-8
Authentication
The PPP protocol suite includes two optional methods (Password
Authentication Protocol (PAP) and Challenge Handshake
Authentication Protocol (CHAP)) to ensure that unauthorized users
do not access network services. By default, authentication is not
required as part of the PPP link process. However if a peer requires
authentication, it must negotiate the use of an authentication
protocol during the link establishment phase.
The manner in which each peer will authenticate the other is
negotiated during the link configuration phase, when each peer
specifies whether it requires authentication and, if it does, the
authentication method it uses. If a link peer requires authentication
(if it is an authenticator, in the terminology of RFC 1334), the other
peer must submit its name and authentication information before
the link can proceed. If the peer fails to send valid authentication
information, the authenticator terminates (closes) the PPP link.
The authentication method used by one peer can be different from
the authentication method used by the other peer. For example, a
peer at one end of a link may require authentication while the other
end of the link may not. Similarly, one end of a link may use PAP to
authenticate peers while the other end uses CHAP.
A PPP interface can support one or both authentication methods. If
you specify that a serial port must use one method but not the other,
the remote peer must authenticate itself according to the specified
authentication protocol. If you specify that a serial port can use
either CHAP or PAP to authenticate a remote peer (that is, both
CHAP and PAP are enabled), the router tries to use CHAP to
authenticate connection requests. If the remote peer does not
support CHAP, the router requires that the remote peer use PAP to
authenticate itself.
Password Authentication Protocol (PAP) – The Password
Authentication Protocol (PAP) provides a simple method for a
peer to establish its identity. A peer being authenticated with
PAP sends Authentication Request messages that contain its
name and PAP password until the authenticator acknowledges
Cayman 2E-H-W User's Guide
November 2000