Explained how -B works and how it works in conjunction with -I or -s.

Reviewed by wiz@

usr.bin/netstat/netstat.1

@@ -1,4 +1,4 @@
-.\"	$NetBSD: netstat.1,v 1.40 2003/08/07 11:15:21 agc Exp $
+.\"	$NetBSD: netstat.1,v 1.41 2005/08/06 11:23:32 rpaulo Exp $
 .\"
 .\" Copyright (c) 1983, 1990, 1992, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
 .\"
-.Dd December 13, 1999
+.Dd August 4, 2005
 .Dt NETSTAT 1
 .Os
 .Sh NAME
@@ -70,6 +70,10 @@
 .Op Fl f Ar address_family
 .Op Fl i
 .Op Fl I Ar Interface
+.Nm
+.Op Fl s
+.Op Fl I Ar Interface
+.Fl B
 .Sh DESCRIPTION
 The
 .Nm
@@ -101,6 +105,20 @@ for debugging.
 With the default display,
 show the state of all sockets; normally sockets used by
 server processes are not shown.
+.It Fl B
+With the default display,
+show the current
+.Xr bpf 4
+peers.
+To show only the peers listening to a specific interface,
+use the
+.Fl I
+option.
+If the
+.Fl s
+option is present, show the current
+.Xr bpf 4
+statistics.
 .It Fl b
 With the interface display (option
 .Fl i ) ,
@@ -362,6 +380,7 @@ accumulated over the preceding interval.
 .Xr ps 1 ,
 .Xr vmstat 1 ,
 .Xr inet 3 ,
+.Xr bpf 4 ,
 .Xr hosts 5 ,
 .Xr networks 5 ,
 .Xr protocols 5 ,