Linux下为KVM 配置桥接设备

还原原始配置

[root@master ~]# route delete default //删除默认网关

[root@master ~]# route -n

Kernel IP routing table

Destination Gateway Genmask Flags Metric Ref Use Iface

192.168.3.0 0.0.0.0 255.255.255.0 U 0 0 0 br0

[root@master ~]# brctl show

bridge name bridge id STP enabled interfaces

br0 8000.525400a7b756 no eth0

[root@master ~]# brctl delif br0 eth0 //断开/删除br0上的eth0设备

[root@master ~]#ifconfig br0 down //让br0设备停止活动

[root@master ~]#brctl delbr br0 //删除br0

root@master ~]# brctl show //查看br0是否依然存在

bridge name bridge id STP enabled interfaces

[root@master ~]# ifconfig eth0 192.168.3.176/24 //重新给eth0分配IP地址

root@master ~]# route add default gw 192.168.3.1 //重新加入默认网关

1234567891011 [root@master ~]# ip addr show

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

inet 127.0.0.1/8 scope host lo

inet6 ::1/128 scope host

valid_lft forever preferred_lft forever

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

link/ether 52:54:00:a7:b7:56 brd ff:ff:ff:ff:ff:ff

inet 192.168.3.176/24 brd 192.168.3.255 scope global eth0

inet6 fe80::5054:ff:fea7:b756/64 scope link

valid_lft forever preferred_lft forever

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(2) 通过配置文件配置桥接设备

配置文件请自行备份

[root@master ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

TYPE=Ethernet

ONBOOT=yes

BRIDGE=br0

[root@master ~]# cat /etc/sysconfig/network-scripts/ifcfg-br0

DEVICE=br0

TYPE=Bridge

ONBOOT=yes

BOOTPROTO=static

IPADDR=192.168.3.176

NETMASK=255.255.255.0

GATEWAY=192.168.3.1

参数详解：

ifcfg-eth0

Device 指定网卡设备名

TYPE 指定网卡的类型为以太网卡

ONBOOT 指定网卡是否开机启动，切记要设置为yes

BRIDGE 指定桥接设备，此处指定为br0设备

建议：以上变量（非变量值）均为大写。

ifcfg-br0

Device 指定网卡设备名

TYPE 指定网卡的类型为桥接

ONBOOT 指定网卡是否开机启动，切记要设置为yes

BOOTPROTO 指定网卡启动如何获取IP地址，设置静态

IPADDR 设置br0绑定的IP地址

NETMASK 设置子网掩码地址

GATEWAY 设置网关

建议： TYPE变量的变量值按照第一个字母大写，其余字母小写的原则，如Ethernet,Bridge

配置完成之后，重启网络服务

如担心干扰，建议停止NetworkManager 服务，这个服务挺讨厌

[root@master ~]# service NetworkManager stop

[root@master ~]#chkconfig NetworkManager off

[root@master ~]# service network restart

[root@master ~]# ip addr show

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

inet 127.0.0.1/8 scope host lo

inet6 ::1/128 scope host

valid_lft forever preferred_lft forever

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

link/ether 52:54:00:a7:b7:56 brd ff:ff:ff:ff:ff:ff

4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN

link/ether 52:54:00:a7:b7:56 brd ff:ff:ff:ff:ff:ff

inet 192.168.3.176/24 brd 192.168.3.255 scope global br0

inet6 fe80::5054:ff:fea7:b756/64 scope link

valid_lft forever preferred_lft forever

查看桥接设备信息

[root@master ~]# brctl show

bridge name bridge id STP enabled interfaces

br0 8000.525400a7b756 no eth0

[root@master ~]# route

Kernel IP routing table

Destination Gateway Genmask Flags Metric Ref Use Iface

192.168.3.0 * 255.255.255.0 U 0 0 0 br0

link-local * 255.255.0.0 U 1004 0 0 br0

default 192.168.3.1 0.0.0.0 UG 0 0 0 br0

由此，桥接设备br0已经配置成功，当创建虚拟机的时候选择虚拟网卡接口的时候选择br0即可



开始安装虚拟机，此时查看桥接设备br0上面的网卡连接情况：

[root@master ~]# brctl show

bridge name bridge id STP enabled interfaces

br0 8000.0025903afe42 no eth0

vnet0

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祝大家顺利！