Require the peer to authenticate itself using PAP [Password
Authentication Protocol] authentication.
.TP
+.B set \fIname\fR=\fIvalue
+Set an environment variable for scripts that are invoked by pppd.
+When set by a privileged source, the variable specified by \fIname\fR
+cannot be changed by options contained in an unprivileged source. See
+also the \fIunset\fR option and the environment described in
+\fISCRIPTS\fR.
+.TP
.B show\-password
When logging the contents of PAP packets, this option causes pppd to
show the password string in the log message.
Sets the ppp unit number (for a ppp0 or ppp1 etc interface name) for outbound
connections.
.TP
+.B unset \fIname
+Remove a variable from the environment variable for scripts that are
+invoked by pppd. When specified by a privileged source, the variable
+\fIname\fR cannot be set by options contained in an unprivileged
+source. See also the \fIset\fR option and the environment described
+in \fISCRIPTS\fR.
+.TP
.B updetach
With this option, pppd will detach from its controlling terminal once
it has successfully established the ppp connection (to the point where