I know I am late at this place, but I am thinking to share my personal experience, I was CCNA certified. I've knowledge of networking but was hesitating in appearing in exam to pass my certification. I've passion of networking then one of my friend told me about certification practice test of https://www.examguarantee.com/ccna.html and I've read material at multiple websites as well as I did practical at lab at my home. I passed my certification exam in first attempt. Thank to him on suggesting this. :)