简介：

KVM创建的虚拟机使用的虚拟网卡可通过Linux中brctl命令将物理网卡绑定到KVM创建的虚拟交换机中，从而实现虚拟机的虚拟网卡与物理网卡实现互通

brctl命令：

Usage: brctl [commands]
commands:
        addbr           <bridge>                add bridge
        delbr           <bridge>                delete bridge
        addif           <bridge> <device>       add interface to bridge
        delif           <bridge> <device>       delete interface from bridge
        setageing       <bridge> <time>         set ageing time
        setbridgeprio   <bridge> <prio>         set bridge priority
        setfd           <bridge> <time>         set bridge forward delay
        sethello        <bridge> <time>         set hello time
        setmaxage       <bridge> <time>         set max message age
        sethashel       <bridge> <int>          set hash elasticity
        sethashmax      <bridge> <int>          set hash max
        setmclmc        <bridge> <int>          set multicast last member count
        setmcrouter     <bridge> <int>          set multicast router
        setmcsnoop      <bridge> <int>          set multicast snooping
        setmcsqc        <bridge> <int>          set multicast startup query count
        setmclmi        <bridge> <time>         set multicast last member interval
        setmcmi         <bridge> <time>         set multicast membership interval
        setmcqpi        <bridge> <time>         set multicast querier interval
        setmcqi         <bridge> <time>         set multicast query interval
        setmcqri        <bridge> <time>         set multicast query response interval
        setmcqri        <bridge> <time>         set multicast startup query interval
        setpathcost     <bridge> <port> <cost>  set path cost
        setportprio     <bridge> <port> <prio>  set port priority
        setportmcrouter <bridge> <port> <int>   set port multicast router
        show            [ <bridge> ]            show a list of bridges
        showmacs        <bridge>                show a list of mac addrs
        showstp         <bridge>                show bridge stp info
        stp             <bridge> {on|off}       turn stp on/off