In this illustration, we see four routers arranged in the shape of a left-leaning rhombus and shaded blue, and two routers shaded gray connecting to the router in the left-most point of the rhombus. The router at the bottom right point of the rhombus is designated R1, the router at bottom left is designated R2, the router at top right is designated R3, and the router at top left is designated R4. R4 connects to two routers: R5 and R6.

Destinations A and D appear to the right of the MPLS routers. A connects to R1, and this connection is labeled 0. R1 connects to R2, and this connection is labeled 0. R2 connects to R4, and this connection is labeled 1. R1 connects to R3 and this connection is labeled 1. Destination D also connects to R3, and this connection is labeled 0. R3 connects to R4, and this connection is labeled 0.

Each of the four MPLS-capable routers is associated with a forwarding table. The forwarding table for R1 appears like this:

The forwarding table for R2 appears like this:

The forwarding table for R3 appears like this:

The forwarding table for R4 appears like this: