I stumbled across this website and find it quite interesting and useful for various certification practice and examination. It contains too much to be mentioned!
Click here (http://www.esnips.com/) to access the website.
You need to search for your choice certification resources. For instance, use 'CCNA' as search term, if you want resources on Cisco Certified Network Associate.
I hope you find it useful. Do not hesitate to share your experience with us.
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