Leinster are next into action at 1.30pm on Saturday, October 9, with a home tie against French side Metro Racing 92.
Munster face a difficult away game later that day when they travel to London Irish for a 5.45pm kick-off.
Reigning champions Toulouse open their title defence against former winners Wasps on the Sunday.
In round 2, Leinster travel to Saracens on Saturday, October 16 for a 5.45pm kick-off, while Munster are at home to RC Toulon earlier in the day.
Ulster travel to Biarritz on the Sunday for their second round game which kicks off at 4pm local time.
Rounds 3 and 4 see the traditional back-to-back home and away fixtures. Ulster are at home to Bath on Saturday, December 11 with the return leg a week later.
Both Leinster and Munster play on Sunday, December 12, with the 2009 champions away to Clermont Auvergne and the 2006 and 2008 champions at home to Tommy Bowe's Ospreys.