10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations match in February, while Alain Rolland is also included in the Elite Panel in what is his last season.
McDermott, who is the IRFU's Elite Player Development Manager will be assisted by Pat Murray while the squad manager will be David Haslett.
Host nation Scotland kick off their campaign against 2002 champions South Africa, and also face England and Russia in their pool matches.
Earlier that day (Fri 11th June), Ireland open their account with a game against Tonga at New Anniesland Stadium in Glasgow (ko 5pm).
Ireland U21 Management. Manager - David Haslett Coach - Mark McDermott Assistant Coach - Pat Murray
The under 21 squad will take part in two warm up games before their departure for the World Cup: Scotland v Ireland, May 22nd, Murrayfield (k.o. 12.45pm) Ireland V Presidents Under 23 XV, May 29th Blackrock RFC (k.o to be confirmed).