In reply to TheDrunkenBakers:
This is perfectly normal behaviour. The trick is to understand why he's barking at 2 and 5.30, and take steps to prevent the barking becoming an ingrained neurotic behaviour.
Bed by 10, at a guess the later barking probably a toilet request. Like people their bladder holding capacity increases with maturity.
2am barking may also be toilet request at present.
Could also be other things depending on his sleeping arrangements, does he sleep in room alone and in dark? Being a young pack animal he might be waking up alone in dark feeling anxious. Calling his pack is a perfectly natural reaction in this situation.
You can try leaving a child's night on for him, and dogs are much happier if you leave a radio on in background for them. Suddenly going from the comforting sounds of having his pack around him to waking up in dark silence is scary for a dog.
If he sleeps in room with people, probably toilet request, hunger, or attention seeking. All of these will diminish with maturity.
Hope that helps