Originally Posted by
megaloman
You'll go through immigration at BOS (your first point of entry), you'll have to collect your luggage and clear customs too, then re-check it for the domestic flight to LAX. Have your return ticket ready to show at check-in in DUB.
There's another nasty surprise at Boston too, I'm afraid: International Arrivals are all funneled through Terminal E (the only CBP location), while AA departures use Terminal B, so there's a terminal change thrown in there.
It's possible to walk from E to B, or take one of the free shuttle buses:
https://www.massport.com/logan-airpo...cting-flights/