deletes all of the bridges at boot time, controller configuration only
persists until XenServer reboot. The configuration database manager
can, however, configure controllers for bridges. See the BUGS section
-of ovs-controller(8) for more information on this topic.
+of test-controller(8) for more information on this topic.
* The Open vSwitch startup script automatically adds a firewall rule
to allow GRE traffic. This rule is needed for the XenServer feature