Don't pretend natd(8) doesn't work with ppp(8) interfaces.

While there's probably a better way to achieve the same,
nothing precludes us from using natd(8) on tun(4) links.

Noticed by:	bde

sbin/natd/natd.8

@@ -1,5 +1,5 @@
 .\" $FreeBSD$
-.Dd June 27, 2000
+.Dd February 28, 2003
 .Dt NATD 8
 .Os
 .Sh NAME
@@ -41,11 +41,16 @@ with
 .Xr divert 4
 sockets under
 .Fx .
-It is intended for use with NICs - if you want to do NAT on a PPP link,
+.Pp
-use the
+(If you need NAT on a PPP link,
+.Xr ppp 8
+provides the
 .Fl nat
-switch to
+option that gives most of the
-.Xr ppp 8 .
+.Nm
+functionality, and uses the same
+.Xr libalias 3
+library.)
 .Pp
 The
 .Nm
@@ -581,6 +586,7 @@ Running the script in the background should be enough to prevent this
 disaster.
 .El
 .Sh SEE ALSO
+.Xr libalias 3 ,
 .Xr divert 4 ,
 .Xr protocols 5 ,
 .Xr rc.conf 5 ,