Rollover vs Crossover: Two Names, One Confusion
The names suggest siblings. The wiring and purposes are unrelated, and using the wrong one achieves nothing.
Quick Answer
| Attribute | Rollover | Crossover |
|---|---|---|
| Wiring | All eight pins reversed | Two pairs swapped |
| Purpose | Console access, serial | Device to device Ethernet |
| Carries | RS-232 serial | Ethernet |
| Typical ends | RJ45 to DB9 or USB | RJ45 to RJ45 |
| Speed | 9600 baud class | Gigabit class |
| Used with | Router and switch console ports | Legacy similar-device Ethernet links |
Why the Confusion Exists
Similar names
Both describe reversed wiring patterns, so the names blur.
Similar look
Both are RJ45 terminated cables. Colour helps: light blue traditionally marks rollover.
Neither works as the other
A rollover in an Ethernet link fails, and a crossover in a console port shows nothing.
Courses cover both
Certification material teaches both, in adjacent chapters.
Choosing Correctly
- Console port on a router or switch: rollover.
- Direct Ethernet link between legacy devices: crossover.
- Anything modern: straight patch cable.
- Check the port label before connecting.
- Colour code your spares to prevent mixups.
Real-World Applications
- Network equipment labs with both types present.
- Field kits for infrastructure work.
- Inventory sorting after migrations.
- Training environments.
Related Guides
For the rollover detail, read rollover cable. For the crossover, see crossover Ethernet cable. For the crossover comparison, start with patch vs crossover.
FAQ
Can a rollover cable connect two computers?
No. It carries serial signals, not Ethernet.
Can a crossover open a console session?
No. The pinout does not match.
Which is more common today?
Rollover, for console work. Crossover is nearly extinct.
How do I tell them apart?
Compare the pin mapping, or check for the DB9 or USB end.