On 12th of October I tried to get CCNA certified by taking the official exam. Now, I didn't succeed since I encountered a major problem: during the simulation exercise I had to configure an ACL based on different requirements. When I entered my first ACE the CLI just didn't accept my syntax and it marked the first IP address as being faulty. I tried different combinations and it didn't work. On a certain moment the CLI went down and I was unable to get back into it for a certain period of time. After this I finally found the issue: this CLI did not accept the protocol type in capital letters. For example: Access-list 101 permit IP host 192.168.2.2 any eq www could not be interpreted. Instead Access-list 101 permit ip host 192.168.2.2 any eq www can be interpreted. Now, I always configured ACL's this way since extended ACL's get complex and it just reads faster when using capital letters to define the protocol type. I must say I was very disappointed to lose about half an hour with this which was the major reason of failure. (missed about 10 questions). Nevertheless, I retook the exam on Thursday 18th and passed with a score of 910.