What Is a Rollover Cable: The Console Cable
Crossover swaps two pairs. Rollover reverses all eight pins, and its purpose is not networking at all.
Quick Answer
| Attribute | Rollover cable |
|---|---|
| Wiring | Pin 1 to 8, 2 to 7, and so on, fully reversed |
| Purpose | Console access to routers and switches |
| Ends | RJ45 to DB9, or RJ45 to USB with an adapter |
| Signal | RS-232 serial, not Ethernet |
| Speed | Typically 9600 baud |
| Typical colour | Light blue, historically |
How It Is Used
Connect to the console port
The RJ45 end goes to the equipment’s console port, not a network port.
Connect the DB9 or USB end
Older setups use a DB9 serial port, newer ones a USB to serial adapter.
Open a terminal
9600 baud, 8 data bits, no parity, one stop bit is the classic setting.
Configure the device
Console access works even when the network configuration is broken, which is the point.
Not to Be Confused With
- Crossover, which swaps two pairs for Ethernet.
- Straight through, the normal network cable.
- Null modem, a DB9 to DB9 equivalent for serial links.
- Standard Ethernet, which rollover does not carry.
Real-World Applications
- Initial setup of routers and switches.
- Recovery of devices with broken network configs.
- Lab work on network equipment.
- Firmware updates over console.
Related Guides
For the pinout, read rollover cable pinout. For the comparison, see rollover vs crossover. For the USB form, start with USB console cable.
FAQ
Is a rollover cable the same as crossover?
No. Rollover reverses all eight pins and carries serial, not Ethernet.
Can I make one?
Yes, by reversing the pin order at one end, but buying one is easier.
Does it connect to network ports?
No. Only the console port, which is clearly labelled.
What settings does the terminal need?
Typically 9600 baud, 8N1.