[root@centos ~]# ./bridge-tool -h

        Provides 1 steps to build or unbuild the bridge network for KVM.
        /tmp/gzexe.xVTDgI4228/bridge-tool [switch [Switch ..]] [switch [Operation]]
        Switch option is not mandatory, default is --eth0.
 
        Switch can be from one of the following:
        --eth0          :only build the bridge network with eth0,build br0.
        --eth1          :only build the bridge network with eth1,build br1.
        --all           :include eth0,eth1.
        -h              :help.
 
 
        Operation option is not mandatory, default is build.
 
        Operation can be from one of the following:
        build           :build the bridge network whith switch network device.
        unbuild         :unbuild the bridge network whith switch network device.