Plug Ethernet cables into the Ethernet ports labeled as 1 and 2 in the diagram. The corresponding ports on the R640XL chassis are labeled as 0 and 1 in the top row of Ethernet ports. If out of band management is to be enabled, the first two built-in ports (1 and 2) at the bottom can be connected. The top row of ports is read from left to right, and is labeled 0 through 1. The bottom row of ports is read from left to right, and is labeled 1 through 4.