Layout > User Interface Basics > Navigating a Layout > To Use the Zoom Port
  
To Use the Zoom Port
1. Click on the Graphics toolbar or click View > Zoom Port. The Zoom Port window opens in the lower-right corner of the graphics window. The portion of the layout that appears in the graphics window is displayed in the Zoom Port in a red box.
2. Click or in the Zoom Port to zoom in or out of the layout. The red box adjusts to show the boundary of the current view of the layout.