在隔离模型工作模式下，其实就是虚拟机软件创建出来一了一个虚拟桥，然后2个虚拟机都连接到这个虚拟桥上来，这样2个虚拟机如果网段相同的话，基本上就可以互相通信了，但是，其不能和宿主机进行通信。更不能和局域网的任何主机通信哟。

　　桥接模型工作模式下，宿主机的网卡被当成交换机来使用了，真正的物理IP被虚拟出来的br0给抢占去了，当虚拟机想要访问局域网的主机是，直接将数据通过eth0（此时，我们可以把它当做交换机来理解）将数据发送到相应的主机上去。

　　多路桥接工作模式下，虚拟机可以根据自己的网络环境，选择相应的网卡将数据发送到想要到达的主机上去。

F>.字符设备选项；

G>.蓝牙相关选项；

H>.Linux系统引导专用选项；

I>.PowerPC专用选项；

J>.Sparc32专用选项；

 

2.创建一个虚拟机实例

 [root@yinzhengjie ~]# mkdir -pv /yinzhengjie/images/vm1

 [root@yinzhengjie ~]# qemu-img create -f qcow2 -o size=100G /yinzhengjie/images/vm1/yinzhengjie_win10.qcow2        #创建一个映像文件

 Formatting '/yinzhengjie/images/vm1/yinzhengjie_win10.qcow2', fmt=qcow2 size= encryption=off cluster_size=

 [root@yinzhengjie ~]# ls -lh /yinzhengjie/images/vm1/yinzhengjie_win10.qcow2

 -rw-r--r--.  root root 194K Sep  : /yinzhengjie/images/vm1/yinzhengjie_win10.qcow2

 [root@yinzhengjie ~]#

 [root@yinzhengjie ~]# yum -y install tigervnc-server

 [root@yinzhengjie ~]# yum -y install tigervnc

 [root@yinzhengjie ~]# qemu-kvm -name "yinzhengjie_windows10" -m  -smp  -hda /yinzhengjie/images/vm1/yinzhengjie_win10.qcow2 -cdrom /yinzhengjie/ISO/cn_windows_10_enterprise_x64_dvd_6846957.iso -boot order=dc

 open /dev/kvm: No such file or directory

 failed to initialize KVM: Operation not permitted

 Back to tcg accelerator.

 VNC server running on `:::'

 [root@yinzhengjie Desktop]# vncviewer :                 #注意，由于我们分配的内存较小，导致图形界面得反应一段时间才能反应过来。

当然我们还可以通过

[root@yinzhengjie ~]# qemu-kvm -name "yinzhengjie_win10" -m 768 -smp 4 -hda /yinzhengjie/images/vm1/yinzhengjie_win10.qcow2 -drive file=/yinzhengjie/ISO/cn_windows_10_enterprise_x64_dvd_6846957.iso,media=cdrom,index=1 -boot order=dc

open /dev/kvm: No such file or directory

failed to initialize KVM: Operation not permitted

Back to tcg accelerator.

VNC server running on `::1:5900'

　　以上的两种方式只是创建出来虚拟机了，但是没有网络接口，没有网卡，就没法和这个虚拟机进行通信，这个时候我们需要给其配置上网卡，由于我们要是使用tap，那么我们必须通过brctl命令帮我们做出来虚拟网卡出来。具体代码如下：

 [root@yinzhengjie ~]# more br100.sh

 #!/bin/bash

 #author :yinzhengjie

 #Blog:http://www.cnblogs.com/yinzhengjie

 #

 brctl addbr br100

 ifconfig eth0  up

 brctl addif br100 eth0

 ifconfig  br100 192.168.2.100/ up

 route add default gw 192.168.2.1

 [root@yinzhengjie ~]#

 运行以上脚本，可以让宿主机多出来一块桥接网卡br100.然后我们需要些一个启动网卡的脚本，具体代码如下：

 [root@yinzhengjie ~]# chmod +x /etc/qemu-ifup

 [root@yinzhengjie ~]#

 [root@yinzhengjie ~]# more /etc/qemu-ifup

 #!/bin/bash

 #author :yinzhengjie

 #Blog:http://www.cnblogs.com/yinzhengjie

 #

 switch=br0

 if [ -n "$1" ];then

    ifcongig $ up

    sleep .5s

    brctl addif $switch $

    exit

 else

    echo "Error:no specifed interface."

    exit

 fi

 [root@yinzhengjie ~]# 

　　写完之后，我们就可以来创建虚拟机了，具体命令如下：

[root@yinzhengjie ~]# qemu-kvm -name "yinzhengjie_windows" -m 786 -smp 4 -drive file=/yinzhengjie/images/vm1/yinzhengjie_win10.qcow2,if=ide,index=0,media=disk,format=qcow2 -drive file=/yinzhengjie/ISO/cn_windows_10_enterprise_x64_dvd_6846957.iso,media=cdrom,index=1 -boot order=dc -net nic -net tap,name=vnet0,script=/etc/qemu-ifup,downscript=no

　　要注意的是上面指定了1个脚本，分别是开启的脚本为/etc/qemu-ifup，还有一个就是关闭的脚本为downscript脚本，当然我们可以不写script参数，因为默认的就是/etc/qemu-ifup,这个脚本是用来启动网卡的，关闭脚本用的是downscript指定，但是如果不指定的就在后面加一个no的参数，这样终止就不会报错啦！

　　当然，我们也可以通过修改配置文件的方式来创建桥接网卡，具体操作如下：

 [root@yinzhengjie network-scripts]# cp ifcfg-eth0 ifcfg-br100

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# more ifcfg-br100

 DEVICE="br100"

 BOOTPROTO="none"

 ONBOOT="yes"

 TYPE="Bridge"

 IPADDR="192.168.2.200"

 NETMAST="255.255.255.0"

 GATEWAY="192.168.2.1"

 DNS1="219.141.136.10"

 DNS2="219.141.140.10"

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# more ifcfg-eth0

 DEVICE="eth0"

 BOOTPROTO="none"

 ONBOOT="yes"

 TYPE="Ethernet"

 BRIDGE="br100"

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# /etc/init.d/NetworkManager stop

 Stopping NetworkManager daemon:                            [  OK  ]

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# chkconfig --list NetworkManager

 NetworkManager     :off    :off    :on    :on    :on    :on    :off

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# chkconfig NetworkManager off

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# chkconfig --list NetworkManager

 NetworkManager     :off    :off    :off    :off    :off    :off    :off

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie network-scripts]# /etc/init.d/network restart

 Shutting down interface br100:                             [  OK  ]

 Shutting down loopback interface:                          [  OK  ]

 Bringing up loopback interface:                            [  OK  ]

 Bringing up interface eth0:  device eth0 is already a member of a bridge; can't enslave it to bridge br100.

                                                            [  OK  ]

 Bringing up interface br100:  Determining if ip address 192.168.2.200 is already in use for device br100...

                                                            [  OK  ]

 [root@yinzhengjie network-scripts]#

 [root@yinzhengjie ~]# modprobe kvm

 [root@yinzhengjie ~]# modprobe kvm_intel

 [root@yinzhengjie ~]# yum -y install qemu-kvm qemu-kvm-tools

 [root@yinzhengjie ~]# ln -sv /usr/libexec/qemu-kvm /usr/sbin/

 `/usr/sbin/qemu-kvm' -> `/usr/libexec/qemu-kvm'

 [root@yinzhengjie ~]# mkdir -pv /yinzhengjie/images/vm1

 mkdir: created directory `/yinzhengjie/images'

 mkdir: created directory `/yinzhengjie/images/vm1'

 [root@yinzhengjie ~]# qemu-img create -f qcow2 -o size=100G /yinzhengjie/images/vm1/yinzhengjie_rhel6.qcow2

 Formatting '/yinzhengjie/images/vm1/yinzhengjie_rhel6.qcow2', fmt=qcow2 size= encryption=off cluster_size=

 [root@yinzhengjie ~]#

 [root@yinzhengjie ~]# yum -y install tigervnc

 [root@yinzhengjie ~]# more /etc/qemu-ifup

 #!/bin/bash

 #author :yinzhengjie

 #Blog:http://www.cnblogs.com/yinzhengjie

 switch=br100

 if [ -n "$1" ]; then

         ifconfig $ up

         sleep 1s

         brctl addif $switch $

         exit

 else

         echo "Error:no specifed interface!"

         exit

 fi

 [root@yinzhengjie ~]#

 [root@yinzhengjie ~]# chmod +x /etc/qemu-ifup

 [root@yinzhengjie ~]#

 [root@yinzhengjie ~]# qemu-kvm -name "yinzhengjie-rhel6" -m  -smp  -hda /yinzhengjie/images/vm1/yinzhengjie_rhel6.qcow2 -net nic -net tap,ifname=yinzhengjie-vnet0,downscript=no -boot order=nc

 VNC server running on `:::'

然后再用VNC打开终端：