I got a train from Brussels central station but I asked for a ticket to Louvain, I didnt specify Louvain la Neuve. So I ended up in Leuven (thats the flemish spelling for Louvain) so I had to buy another ticket from Leuven to LLN! Doh!!
To get to Louvain-la-Neuve by train, as many people do, for the most part, you must change trains at Ottignies, a teensy little town southwest of LLN's center. Technically, it's all the same town.
Ottignies is on the Brussels-Namur-Luxembourg Intercity line, so there is near-constant activity. But if you don't time it right, you could be hanging out at Ottignies for a very long time.
The name of the train station is Louvain La Neuve Universite. LLN is approximately 35 km from Brussels