Contributed by Jacques Goldman.

Attempts to start pppd systematically fail from Linux on servers 
such as the popular and defunct Shiva LanRover series, 
when one or more of the following conditions are met:
 
 1-Shell authentication is not enabled on the server (thus a username
 prompt never occurs while the script expects it).

 2-An entry exists in the Linux machine with an entry in
     /etc/ppp/chap-secrets
 compatible with the attempted connection ( such as "me * mypassword", 
 or explicit server IP name/address in place of the *).

 3-The user has not set a valid entry in:
     /etc/ppp/pap-secrets

For these reasons I believe people should always try a dial up script 
which does doe not expect prompts and 
has a valid entry for the desired ISP in only pap-secrets.

Explanation: 
 1) with Shell Authentication the username and password go unencrypted.
Some administrators rightly do not like it, so they disable the feature.
 2) the server then tries proprietary SPAP unsupported under Linux, falls
back to trying MS-CHAP with a special encrypting method not understood by
CHAP support even in the most recent pppd, and finally falls back on
trying PAP which happens (what a luck) to always work.
 3) the server hangs the line when no method yielded a positive
acknowledge. It thus sometimes looks as if the modem is to be blamed.

