Packet Tracer is a simulation tool designed by Cisco that lets you create network topologies. I have found it to be really good for simulating a most switching and routing environments. I create as many labs as possible in PacketTracer. It can do about 98% of the lab work I need to do. There are some IOS commands it just doesn't support. In those cases I'll use GNS3 for mocking up networks.
Packet Tracer 60 second download and install:
- Go to the netacad.com website
- Click "Enroll to download Packet Tracer"
- Click "Sign up today!"
- Enter any information in the mandatory fields and click "Create Account"
- Close the popup that says "Launch Course"
- Scroll to the bottom of the page
- Click "Packet Tracer - Access resources on installing and using this learning tool."
- Download and install the appropriate version
- Run your eConfigs Labs!