In this illustration, we see a system of five routers arranged in a pentagon and connected with black lines representing interface links. A packet of data with a number designation of 0110 arrives at the left-most router. This router is associated with a forwarding table, which appears as:

Above the forwarding table is an oval labeled "Routing algorithm," with an arrow pointing down from it to the forwarding table. A red line indicates that this particular packet will be forwarded along interface link 2, where it will arrive at the next router. All the routers are associated with their own forwarding table and routing algorithm. A dotted horizontal line separates the control plane (above the line) from the data plane (below the line); the routing algorithm originates in the control plane and sends its information to the forwarding table in the data plane.