diff --git a/etc/neutron_vpnaas.conf b/etc/neutron_vpnaas.conf
index b3b323db8..61a892a14 100644
--- a/etc/neutron_vpnaas.conf
+++ b/etc/neutron_vpnaas.conf
@@ -5,7 +5,8 @@
 # List of allowed service types includes VPN
 # Combination of <service type> and <name> must be unique; <driver> must also be unique
 # This is multiline option
-service_provider=VPN:openswan:neutron_vpnaas.services.vpn.service_drivers.ipsec.IPsecVPNDriver:default
+# Reference implementation
+# service_provider=VPN:openswan:neutron_vpnaas.services.vpn.service_drivers.ipsec.IPsecVPNDriver:default
 # Uncomment the following line (and comment out the OpenSwan VPN line) to enable Cisco's VPN driver.
 # service_provider=VPN:cisco:neutron_vpnaas.services.vpn.service_drivers.cisco_ipsec.CiscoCsrIPsecVPNDriver:default
 # Uncomment the following line (and comment out the OpenSwan VPN line) to enable Brocade Vyatta's VPN driver.