I have been designing training labs using Cisco's Packet Tracer for over a year, and I have found it to be a superior routing and switching simulator for CCNA students. Beyond the obvious advantages of portability, taking very little space, low power consumption, and generating no heat this simulator has a number of other powerful features for students and instructors alike. These features include the activity wizard, a simulation mode, and a multiuser mode. Let's take a closer look at these additional features.
Activity Wizard:
This feature allows the lab creator to create standalone labs with built in instructions and lab testing, making Packet Tracer not only an excellent routing and switching simulator but also an outstanding Training tool and testing engine. The following are some of the capabilities of this training tool:
Simulation Mode:
This feature permits the student to select different types of traffic, and view the packets as they transvers the network from device to device. This provides a tool similar to WireShark and is an excellent way to demonstrate how packets move through a network.
Multiuser Mode:
This is an assume feature, it permits the instructor and students to link their individual labs on their computer together creating one large network. The instructor and students can then send different types of traffic between their labs. The possibilities of this feature are incredible for a classroom training session. Although I have not tried it I am sure that this could be done through the Internet as well creating endless possibilities for an online training course.
In conclusion Packet Tracer may not have all the advanced BGP command available in simulators such as GNS3, but it does have excellent level 3 switching support that is not available from the competition, and while real hardware can provide all of this, real hardware has none of the features described above so Packet Tracer is not only an outstanding routing and switching simulator to model your network, but is by far the superior choice for CCNA students and trainers trainers and students alike.