Today I successfully passed the exam. I got a score of 420. Alhamdulillah.
How I studied for the exam: I watched the Vmware E-learning fundamental videos, took notes, reviewed them with a big mind map, then registered and sat for it. I sat studying in many small sessions.
It’s great to sit for an exam and pass it from home :) it’s also great to see there are other folks out there who are sharing the same experience.

Troubleshooting
I first thought about an issue about DNS on CUCM. I remembered that, during the CUCM installation, I put CUCM somewhere.
So I went to every corner of CUCM admin pages, where I could find the “CUCM” keyword.
I changed some settings in Entreprise Parameters. I even tried to change the hostname under the CUCM CLI mode:
Then, I examined what’s happening at the router level, with “debug mgcp events”. I noticed this line:




Later, I will change these values because my router lacked memory resources.
To verify the aforementioned settings:
Let’s create our first ephone-dn:
At this point, my router displayed an error message indicating a lack of memory. I increased its memory size in GNS3:
After a reload, things went ok
I also reduced the max-ephone and max-dn values:
Now we can add ephone-dns without problems:
When I create a dual-line ephone-dn, two “sub-ephone-dn” are created:
To verify ephone-dns:
another way to verify it:
Notice that there are two channels for ephone-dn 2, which is a dual-line ephone-dn.