Click the Supports Link button 
on the diagram toolbar.
On the Diagram, click the source component element.
Drag the link to the destination interface element.
Drop when the destination element is highlighted.
A supports relationship is the relationship a component has to the implemented interfaces, and can only be drawn from a component to an interface.
To create a supports link:
Click the Supports Link button
on the diagram toolbar.
On the Diagram, click the source component element.
Drag the link to the destination interface element.
Drop when the destination element is highlighted.
Related Topics:
Creating Links
Moving Links
Editing Links