You can bridge interfaces in pfSense by navigating to Interfaces | (assign) and clicking on the Bridges tab. On this tab, there is a table displaying all the configured bridges. To add a new bridge, click on the Add button under the table.
On the Bridge Edit page, you need to select at least two interfaces (you can bridge more than two interfaces); you can select them in the Member Interfaces listbox. The interfaces selected are the ones that will be bridged. You may also enter a brief description in the Description field.
Clicking on the Display Advanced button reveals a number of advanced options you can configure. The ...