（四）KVM配置桥接网卡
配置桥接网卡
添加桥接网卡br0，注释掉已有的eth0配置
[root@ubuntu01 ~]# vi /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
#auto eth0
#iface eth0 inet dhcp
auto br0
iface br0 inet static
address 192.168.31.10
netmask 255.255.255.0
broadcast 192.168.31.255
gateway 192.168.31.2
bridge_ports eth0
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off
重启网络后，就可以看到桥接网卡的配置了：
[root@ubuntu01 ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29acc95e no eth0
virbr0 8000.000000000000 yes
[root@ubuntu01 ~]# ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000
link/ether 00:0c:29:ac:c9:5e brd ff:ff:ff:ff:ff:ff
inet6 fe80::20c:29ff:feac:c95e/64 scope link
valid_lft forever preferred_lft forever
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:0c:29:ac:c9:5e brd ff:ff:ff:ff:ff:ff
inet 192.168.31.10/24 brd 192.168.31.255 scope global br0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feac:c95e/64 scope link
valid_lft forever preferred_lft forever
4: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 32:33:c1:58:2a:87 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
或者，用virsh 创建桥接网卡
virsh iface-bridge
相比于手动配置，好像用virsh配置桥接网卡可以不用重启网络
[root@ubuntu01 ~]# virsh iface-bridge --interface eth0 --bridge br0
Created bridge br0 with attached device eth0
Bridge interface br0 started
[root@ubuntu01 ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29acc95e yes eth0
virbr0 8000.000000000000 yes
[root@ubuntu01 ~]# virsh iface-list
Name State MAC Address
---------------------------------------------------
br0 active 00:0c:29:ac:c9:5e
lo active 00:00:00:00:00:00
[root@ubuntu01 ~]# ip ad
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000
link/ether 00:0c:29:ac:c9:5e brd ff:ff:ff:ff:ff:ff
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 12:c0:91:80:ba:d6 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:0c:29:ac:c9:5e brd ff:ff:ff:ff:ff:ff
inet 192.168.31.132/24 brd 192.168.31.255 scope global br0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feac:c95e/64 scope link
valid_lft forever preferred_lft forever
自动生成网卡配置：
[root@ubuntu01 ~]# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto br0
iface br0 inet dhcp
bridge_ports eth0
bridge_stp on
bridge_fd 0
如果删除桥接网卡：
[root@ubuntu01 ~]# virsh iface-unbridge br0
这个操作会导致宿主机断网，需要手动重启一下eth0网卡
创建虚拟机
virt-install 的--network选项指定bridge：
[root@ubuntu01 ~]# virt-install
--name=centos_vm_01
--virt-type=kvm
--ram=1024
--cdrom=/data/iso/CentOS-V6.5.23.iso
--disk path=/data/img/disk01.raw
--network bridge=br0
--graphics vnc,listen=0.0.0.0
--noautoconsole
