To pass the cisco CCNA test, tester need to demonstrate ability to configure and trouble-shoot the network devices such as routers, switches etc. Unfortunetly, setting up a cisco lab at home is expensive. Fortunetly, cisco provide us an virtue lab, a software called packet tracer, which simulates the behavior of the real-world devices.
You can drag and drop virtue routers, switches, cables onto the panel, and connet them with virtue cables. You can take a close look at a virtue device (photos taken from the real-world devices) or open the CLI to practice the cisco IOS commands.
In a short words, Packet Tracer simulates physical equipment and provides students learning opportunities that are obtained in the real-world office or lab.
Packet Tracer 5.1 is the latest version, which can be downloaded from Cisco Networking Academy’s website.
I have created a seriers of easy to follow video tutorial on how to use Packet Tracer for CCNA certification.
How to Download Packet Tracer 5.0.
CCNA Lab Video Tutorial