Given a travel related situation, and given a specific question about the situation, summarize the question into a title
Q: Most questions related to port of entry that I've seen around here are asked in the context of visiting the country and not visiting the issuing country. Mine is different.

This is the first time I'm travelling to Europe. I'm travelling to Italy and Greece (7 nights in Italy, 8 nights in Greece) via Air France flights. I'll first land in Paris CDG airport from Bangalore, India and then I catch a connecting flight Air France flight to Rome, Italy (4 hours gap between flights). I've been issued a Schengen Visa from Greece (as I'll spend the longest duration in Greece) and I'll NOT be deviating from the itinerary presented to Greece Embassy.

Where should I clear my immigration to get the Schengen entry stamp on my passport? Someone told me that I should clear immigration in CDG Paris, but was not sure about this. Could someone clarify this for me? Assuming the above is the case, I also have a follow up question. What if both my flights arrive and depart from the same terminal in CDG Paris?

A:
First port of entry a Schengen Visa (connecting flights)