Brctl Command

Bridges


View


To view the current bridges, use the following command on a SSH/Telnet terminal:


 brctl show

The command will then output a bridge name (Often br0 or br1), bridge ID (Used to uniquely specify the bridge), and the current settings for STP (Spanning Tree Protocol). The output wil be formated similar to this:


 bridge name     bridge id               STP enabled
br0 8000.001217318d3e yes

Add


A bridge can be added using the following command, with <name> being replaced with the name of the bridge being replaced.


 brctl addbr <name>

Delete


Where name is the user specified name of the bridge. To delete a bridge, one would use


brctl delbr <name>


Interfaces


Although the preceding commands simply create an instance of a bridge, in order to use them, one must add interfaces to a bridge. The bridge "br0" is standard bridge on DD-WRT.


Show


In order to show the current interfaces that are members of a bridge, we use a command similar to the "show" command:


 brctl showbr br0 (for V23SP2: brctl showstp br0)

This would generate output similar to the following:


 br0
bridge id 8000.001217318d3e
designated root 8000.001217318d3e
root port 0 path cost 0
max age 20.00 bridge max age 20.00
hello time 2.00 bridge hello time 2.00
forward delay 0.00 bridge forward delay 0.00
ageing time 42.30 gc interval 4.00
hello timer 1.28 tcn timer 0.00
topology change timer 0.00 gc timer 2.02
flags

vlan0 (1)
port id 8001 state forwarding
designated root 8000.001217318d3e path cost 100
designated bridge 8000.001217318d3e message age timer 0.00
designated port 8001 forward delay timer 0.00
designated cost 0 hold timer 0.00
flags

eth1 (2)
port id 8002 state forwarding
designated root 8000.001217318d3e path cost 100
designated bridge 8000.001217318d3e message age timer 0.00
designated port 8002 forward delay timer 0.00
designated cost 0 hold timer 0.00
flags

Here we can see that the bridge contains two members, eth1 and vlan0.


Add


To add a interface to a bridge, the command syntax is


 brctl addif <brname> <ifname>

Where <brname> is the existing bridge name, and ifname is the interface you want to add.


Remove


To remove a interface from a bridge, the syntax is very similar


brctl delif <brname> <ifname>


 


Source:http://www.dd-wrt.com/wiki/index.php/Brctl_command