Cisco Packet Tracer
A digital lab where you can build and test computer networks without needing real equipment.
Free
By: Cisco
Pros
- Free.
- Virtual lab.
- Many devices.
- Many protocols.
- Troubleshooting help.
- Works offline.
Cons
- Not fully real.
- Needs NetAcad (officially).
- Mostly Cisco.
- Not for complex setups.