This drill is specifically for defense. The focus is on footwork and quick puck movement. Have the defense split up into pairs. Set up as shown in the diagram. On the whistle, D2 takes 1 or 2 strides towards D1 and then transitions backwards. D1 dumps a puck lightly off to one side of D2. D2 needs to open up and transition forwards to go receive the puck. They should recieve the puck and turn up ice as quick as possible to give a pass back to D. D2 then skates up to D1 and transitions backwards to repeat the same thing. Have players do this for 20 to 30 seconds before switching roles.
It is also a good idea to teach the defense to use an escape move as they retrieve the puck against the boards. The players should pretend there is a forechecker attacking them and fake one way before spinning out the other way, taking a few explosive strides up ice and then making the pass back to the other defense.