The itinerary lasts 3hrs 00min, and has 1 steps, and it will cost 17 euros minimum.

Bordeaux - Carcassonne
The step from Bordeaux to Carcassonne lasts 3hrs 00min. You'll travel in a INTERCITÉS operated by SNCF Voyageurs.
On board, you'll have access to: Wi-Fi, Drinks and snacks, Bike.
You can find tickets from 17 euros if you book 2 months in advance.