[ovs-discuss] How to keep/update pre-configured flows when connecting to an OVS controller?

[Ben Pfaff]

On Thu, May 08, 2014 at 01:42:10PM +0800, Ji Li wrote:
> remote configuration of the openflow rules. Before connecting OVS bridge to
> the controller, there are already some basic flow configurations for the
> OVS bridge.
> e.g. flowA, flowB for br0
> 
> After I connect OVS bridge with the OpenDaylight controller:
> # ovs-vsctl set-controller br0 tcp:***
> 
> I will find the previous configured old flows (flowA, flowB) are totally
> deleted. I try to use the monitor command of ovs-ofctl to monitor the flow
> changes when connecting to a controller:
> 
> # ovs-ofctl monitor br0 watch:
> ...
> NXST_FLOW_MONITOR reply (xid=0x0):
>  event=DELETED, reason=delete, table=0 ...
> ...
> 
> I can get some events of DELETED indicates the flowA and flowB are deleted
> by someone, does OpenvSwitch itself or the controller delete those flow?
> Actually I find the flows will also be totally deleted after the OVS bridge
> is disconnected from the controller.
> 
> Those pre-configured rules are important for my setup, is there any way to
> keep these old flows after connecting to a controller?

Open vSwitch deletes all the flows if you change its configuration
from "no controllers" to "at least one controller" or vice versa.
However, a controller that can't be reached still counts as "at least
one controller".  So: you could configure an invalid controller (an IP
address or port that is not reachable), add your flows, and then
configure your correct controller.