MicroStation DGN files can be saved with nonstandard file extensions to denote content; for example, you can save a DGN file with a .par extension to identify drawings containing parcel information. By default, only files with a .dgn file extension are shown in the Catalog window.
To configure ArcGIS for Desktop to recognize these nonstandard DGN files as CAD datasets, enable the Examine all file extensions option in the ArcCatalog Options dialog box.
- Start ArcCatalog or ArcMap.
- Click Customize on the main menu and click ArcCatalog Options or ArcMap Options.
- Click the CAD tab.
- Check the box Examine all file extensions to display all DGN files. Uncheck it to display only DGN files saved with the .dgn extension.
- Click OK to close the dialog box.