Rollover Cable Pinout: Pin by Pin
One table settles every rollover question, and a tester confirms any cable against it.
Quick Answer
| RJ45 pin (end A) | RJ45 pin (end B) |
|---|---|
| 1 | 8 |
| 2 | 7 |
| 3 | 6 |
| 4 | 5 |
| 5 | 4 |
| 6 | 3 |
| 7 | 2 |
| 8 | 1 |
Every pin maps to its mirror. No pair survives intact, which is why the name is rollover.
The DB9 Equivalent
Adapter end
The RJ45 to DB9 adapter continues the reversal into the serial pinout.
Console signals
Receive, transmit and ground are what matter at 9600 baud.
USB adapters
Modern cables integrate the serial chip, appearing as a COM port.
Pin numbering caution
DB9 numbering is viewed from the socket side. Double check before wiring.
Verifying a Rollover Cable
- Set a wiremap tester to custom mode if it has one.
- Expect pin 1 to map to 8, and so on down the line.
- A straight reading means someone made a patch cable by mistake.
- Label the cable once confirmed.
- Keep it with console equipment, not network spares.
Real-World Applications
- Building or repairing console cables.
- Verifying inherited cable stock.
- Lab setups for network equipment.
- Troubleshooting console connections.
Related Guides
For the cable’s purpose, read rollover cable. For the comparison, see rollover vs crossover. For the USB form, start with USB console cable.
FAQ
What does the tester show?
A mirrored mapping, pin 1 to 8 down the line.
Why is my console session dead?
Wrong cable type, wrong COM port settings, or a damaged end.
Can I use a crossover instead?
No. The pinouts are completely different.
Does colour matter?
Only for identification. Light blue is traditional.