Linux® For Dummies®, 8th Edition

Step 5: Build a Bridge

Building the bridge is possibly the most complicated of all the steps. Unfortunately, there aren’t any fancy graphical tools to help you out here. You have to dig into the Fedora command line and do things the old-fashioned way — typing commands one by one at the command prompt.

The Linux Ethernet bridging command you need to use is brctl. This command allows you to create a network bridge, add network interfaces to the bridge, and monitor the bridge.

The format of the brctl command is

 brctl [command]                                                     

where command is the bridging command to execute. The brctl commands you’ll use are shown in Table 19-1.

Table 19-1. The brctl Commands

Command	Description
addbr	Create a new network bridge
delbr	Remove an existing network bridge
addif br if	Add network interface if to bridge br
delif br if	Remove network interface if from bridge br
stp br state	Set the spanning tree protocol for bridge br to on or off

To execute command line commands, you’ll need to open a Terminal session:

1.	Click ApplicationsSystem ToolsTerminal. The Terminal tool appears, showing a command line prompt.
2.	If you are not already logged in as the root user, you must become the root user. To do that at the command line, type su, and then enter the root password. The command line prompt changes to a pound ...