Open Stack

Hi

I created an instance using OpenStack.
Then, we set up Floating IP and added a rule enabling ping command and 
ssh command.
However, it can not communicate with the instance.
As I looked it up, the DHCP agent was not running on the Compute node. 
Also, the OpenvSwitch agent was not started.
However, on the Controller node, the DHCP agent was running.
In order to communicate with an instance, what kind of setting should be 
made to the Compute node?
DHCP agent, OpenvSwitch agent setting method is not clear well.

Could you give me a professor?

Thanks.