I have not done it yet, but I read that the train only goes to the border, then you walk across, and catch a Vietnamese train on the other side. I believe the bus is more frequent and goes through to Hanoi. Have you checked seat61.com?
(from Wiki)
Nanning has two major bus terminals:
* Langdong bus terminal is on Minzu Dadao to the east of the city centre amongst all the new skyscrapers.
* Jiangnan bus terminal is on Xingguang Dadao way south of the city center. Buses from the south, Pingxiang near the Vietnam border (arrivals roughly hourly, 2.5 hrs, ¥60), and Yangshuo (via Guilin) operate from Jiangnan. Getting there/away: Bus 41 (¥3, 20 minutes journey) connects Jiangnan to Chaoyang Road in the city centre. Catch them from the square in front of the terminal. Alternatively a taxi will take you for approx. ¥5-10.
* Yunde buses from Hanoi arriave at Langdong Bus Station.
* There are also direct buses to Nanning from Haiphong and Ha Long Bay.
Last edited by Daawgon; Mar 25, 2010 at 5:52 pm