The four Irish sides have all made it to the quarter final stages of the Celtic League, which are due to be played on December 1.
The quarter final draw is:
Leinster v Newport
Ulster v Neath
Connacht v Glasgow
Munster v Llanelli.
Leinster, Ulster, Munster and Connacht will all enjoy home advantage in the quarter finals, having finished first and second in their respective Pools.
The semi finals will be Leinster or Newport v Connacht or Glasgow and Munster or Llanelli v Ulster or Neath.
In the weekend's games Munster demolished Cardiff by 51-10, Leinster beat Swansea 34-18, Ulster overcame Pontypridd 29-20 while Connacht whitewashed Caerphilly by 62-0.