E-Labs are a form of practice in the use of a router, a piece of hardware on an inter-computer network that actively monitors and reroutes data, that was developed by Cisco Networking for use in teaching the art of networking to students. They are employed many times as teaching aids to enrich the course material for the Cisco Networking Academy. The e-Labs provide a hypothetical router interface, complete with all possible commands that a normal router can process (with the exception of data-destructive ones, such as the "delete flash" command, or the "erase running configuration" command). The e-Lab is often more helpful than the regular hands-on lab, in that the lab is a flash file that guides you in the right direction by giving you specific instructions on what to tell the "router" to do. If you enter incorrect answers, it will prompt you to try again. This can also be interpreted as a hinderance, because no e-Lab allows you to have total control over the "router". For that, students are provided with expensive Cisco routers, bridges, hubs, switches, and more while in class. There, the student is working in a professional-type environment, and is able to access all of the state-of-the-art equipment made by Cisco (and their divisions). e-Labs are only made by Cisco, and are only available to people enrolled in the Cisco Networking Academy as either students or instructors. e-Labs are also available as a suplement to the printed copy of the online course (which is the exact same thing, only on paper) in a CD in the back of the book.
Personal Opinions on "e-Labs" held by QuietLight: I am a member of the Cisco Networking Academy, and as part of my training I am required to do these activities by my instructor. I have completed around 30 so far, and the are truly a pain to do. The script does not accept any abbreviated commands (ie- using "ins-pass" as a shortcut, whereas e-Labs make you type out the whole "insert-password" command), which means less practice using the commands that I will actually use in a real router setup, and more work for my hands. Also, the flash files are immensely detailed, which makes for a slow response time on my computer, and frequent crashes. Given the option, I would prefer to work on a real router.