This a good VPN source

				# This file defines the set of CIDRs (network/mask-length) to which				# we will communicate in the clear, or, if the other side initiates IPSEC,				# using encryption.  This behaviour is also called "Opportunistic Responder".				#				# See @FINALDOCDIR@/policygroups.html for details.				#				# $Id: clear-or-private.in,v 1.4 2003/02/17 02:22:15 mcr Exp $				#