-ovs-vswitchd is the most sophisticated of ofproto's clients, but
-ofproto can have other clients as well. test-openflowd, in the
-"tests" directory, is much simpler than ovs-vswitchd. It may be
-easier to initially bring up test-openflowd as part of a port.
+The default "fail-mode" for Open vSwitch bridges is "standalone",
+meaning that, when the OpenFlow controllers cannot be contacted, Open
+vSwitch acts as a regular MAC-learning switch. This works well in
+virtualization environments where there is normally just one uplink
+(either a single physical interface or a bond). In a more general
+environment, it can create loops. So, if you are porting to a
+general-purpose switch platform, you should consider changing the
+default "fail-mode" to "secure", which does not behave this way. See
+documentation for the "fail-mode" column in the Bridge table in
+ovs-vswitchd.conf.db(5) for more information.