A switch to router connection requires a straight-through cable. Straight-through cables are also used for host to switch communication.

A crossover cable is used to connect "like" devices, and a straight through cable is used when connecting "unlike" devices. The one exception to this rule is when connecting a computer NIC to an Ethernet port on a router, a crossover cable is used. In summary, the following list describes when to use crossover and straight through cables:
* Host to host - Crossover
* Host NIC to router - Crossover
* Host to switch - Straight through
* Switch to Switch - Crossover
* Switch to router - Straight through