Chord D11 notes: D, G, C and E. You must leave out the 6th and 5th strings.

The strings 4(D), 3(G) and 1(E) are left open.

Observation: the D11 (D dominant 11th) chord should include a 3rd, but it is often omitted - transforming it into a simple D9sus4 or D9sus.

Steps: 1-3-(5)-b7-9-11.
1(D), 3(F#/Gb), 5(A), b7(C), 9(E), 11(G).