Which Cable to Use?

Table 4-2 describes which cable should be used when wiring your devices together. It is important to ensure you have proper cabling; otherwise, you might be giving yourself problems before you even get started.

Table 4-2. Determining Which Cables to Use When Wiring Devices Together

If device A has a:	And device B has a:	Then use this cable:
Computer COM port	Console of router/switch	Rollover
Computer NIC	Switch/hub	Straight-through
Computer NIC	Computer NIC	Crossover
Switch or hub port	Router's Ethernet port	Straight-through
Switch or hub port	Switch or hub port	Crossover (check for uplink button or toggle switch to defeat this)
Router's Ethernet port	Router's Ethernet port	Crossover
Computer NIC	Router's Ethernet port	Crossover
Router's serial port	Router's serial port	Cisco serial DCE/DTE cables

Table 4-3 lists the pinouts for straight-through, crossover, and rollover cables.

Table 4-3. Pinouts for Different Cables

Straight-Through Cable	Crossover Cable	Rollover Cable
Pin 1 Pin 1	Pin 1 Pin 3	Pin 1 Pin 8
Pin 2 Pin 2	Pin 2 Pin 6	Pin 2 Pin 7
Pin 3 Pin 3	Pin 3 Pin 1	Pin 3 Pin 6
Pin 4 Pin 4	Pin 4 Pin 4	Pin 4 Pin 5
Pin 5 Pin 5	Pin 5 Pin 5	Pin 5 Pin 4
Pin 6 Pin 6	Pin 6 Pin 2	Pin 6 Pin 3
Pin 7 Pin 7	Pin 7 Pin 7	Pin 7 Pin 2
Pin 8 Pin 8	Pin 8 Pin 8	Pin 8 Pin 1