I will be arriving at Fiumicino T3 on an Alitalia flight from London and departing 2 hours later from Fiumicino T1 on an Alitalia flight to Palermo. My Alitalia ticket is from London to Palermo and I will have a checked-in bag.
Am I correct in believing that I have to exit T3, go to T1 and through its passport control and security for the connecting flight?
What is the quickest way to get from T3 to T1, and what is the approximate time needed to do so?
All information and advice gratefully received!