Ulster will play Irish interprovincial rivals Munster in the quarter-finals of the Heineken Cup on Sunday 8 April.
The sides will clash at Thomond Park at 1345 BST after Munster qualified as top seeds and Ulster as eighth seeds after the final series of pool games.
Leinster will host Cardiff Blues at the Aviva Stadium, Edinburgh are at home to Toulouse and Saracens will entertain Clermont Auvergne.
Munster or Ulster will host Edinburgh or Toulouse in the semi-finals.
If Leinster overcome Cardiff at the last eight stage, they will be away to Saracens or Clermont at the last four stage.
The last eight ties will be played on the weekend of 6-8 April, with the semi-finals on the weekend of 28-29 April.
Munster's win at Northampton and Leinster's win over Montpellier on Saturday left Ulster's interprovincial rivals as the top two seeds for the knockout stage of the competition.
Ulster finished second in Pool 4 after their 19-15 defeat at the hands of Clermont Auvergne.
Ulster also reached the quarter-finals of last year's competition but lost to eventual finalists Northampton.
Leinster coach Joe Schmidt said his side would have to "go up another level" in their clash against Cardiff.
"Cardiff will travel to Dublin in high spirits after their performances over the group stages," said Schmidt.
"We were lucky to get a win in Cardiff City Stadium a few weeks ago and they didn't bring a full strength side when we faced them in the RDS earlier this year.
"With a few players to come back into their side they will be formidable opponents."