Having broken his duck in Reading's previous game, a 3-0 win at Grimsby, Forster was quickly back into the goalscoring habit.
His first came on 28 minutes when Ricky Newman's sweet free-kick was flicked home by the alert striker, who rose highest in a crowded penalty area.
Ipswich had chances to cancel out the opener, but found Reading's American goalkeeper Marcus Hahnemann in fine form.
The giant gloveman particularly caught the eye when he superbly pushed away Matt Holland's free header as Reading were for once caught out at the back.
But the home side dominated and deserved their two-goal half-time lead, which came courtesy of a stunning strike from Forster.
The striker picked up a pass from Anthony Rougier and left John McGreal standing as he cut inside and fired into the far corner of the net beyond the desperate dive of Andy Marshall.
Caretaker manager Tony Mowbray clearly had harsh words to say at half time as Ipswich came out fighting after the break.
Impressive teenage midfielder Darren Ambrose briefly brought them back into contention when he rifled home a cracking 30-yard free-kick after Forster was adjudged to have fouled Jamie Clapham.
But that fighting spirit was taken too literally by Spanish striker Pablo Counago, whose petulant shove on Adie Williams was punished by an instant red card and two minutes later Ipswich's brief comeback was over.
James Harper played a neat ball through a sleepy Ipswich defence and Forster was on to it in a flash, shrugging off appeals for offside to beat Marshall with a neat, low finish.