-/etc/ppp/auth-up was previously executed. It is executed in the same
-manner with the same parameters as /etc/ppp/auth-up.
-.TP
-.B /etc/ppp/ip-up
+/etc/ppp/auth\-up was previously executed. It is executed in the same
+manner with the same parameters as /etc/ppp/auth\-up.
+.TP
+.B /etc/ppp/ip\-pre\-up
+A program or script which is executed just before the ppp network
+interface is brought up. It is executed with the same parameters as
+the ip\-up script (below). At this point the interface exists and has
+IP addresses assigned but is still down. This can be used to
+add firewall rules before any IP traffic can pass through the
+interface. Pppd will wait for this script to finish before bringing
+the interface up, so this script should run quickly.
+.TP
+.B /etc/ppp/ip\-up