The Link Tool can be activated either from the Link Tool item of the Edit Menu or from the Link Tool button in the Edit Mode Tool Bar (the button shown in Figure 1).
When the Link Tool is activated (when the Link Tool button is pressed) you can drag a link from one node to another in the Network Pane: Press the left mouse button somewhere within one node and drag the cursor into another node. Then, release the mouse button again. When you have created the link, the select tool is normally activated again. If you want to keep the Link Tool activated (to create a series of links) hold down the SHIFT key while creating the link.