Control Plan and Data Plan - Answer provided by Keith Barker

I came across this great answer to a question from Keith Barker and felt it needed to be shared. Great analogy Keith.

Correct AnswerRe: What is control plane and data plane

Hello Vijay-

Great question.

Let's say you and I are in charge of public transportation for a small city.

Before we send bus drivers out, we need to have a plan.

Control Plane = Learning what we will do

Our planning stage, which includes learning  which paths the buses will take, is similar to the control plane in the network.   We haven't picked up people yet, nor have we dropped them off, but we do know the paths and stops due to our plan.  The control plane is primarily about the learning of routes.

In a routed network, this planning and learning can be done through static routes, where we train the router about remote networks, and how to get there.   We also can use dynamic routing protocols, like RIP, OSPF and EIGRP to allow the routers to train each other regarding how to reach remote networks.   This is all the control plane.

Data Plane = Actually moving the packets based on what we learned.

Now, after the routers know how to route for remote networks, along comes a customers packet and BAM! this is were the data plane begins.   The data plane is the actual movement of the customers data packets over the transit path.   (We learned the path to use in the control plane stage earlier).

Best wishes,

Keith

The original post can be found here https://learningnetwork.cisco.com/thread/33735