CentOS6.3 KVM下设置网卡为桥接模式

CentOS6.3 KVM下设置网卡为桥接模式 KVM的默认网络模式为NAT，就是说借助宿主机模式上网，现在我们想改成桥接模式，这样外界就可以直接和宿主机里的 虚拟机通讯了。 1，首先看一下默认的网络设置 # cat /etc/libvirt/qemu/networks/default.xml <network>   <name>default</name>   <uuid>1f118032-0345-4725-adcf-6b94f6aca19c</uuid>   <bridge name="virbr0" />   <mac address='52:54:00:F1:6B:6E'/>   <forward/>   <ip address="192.168.122.1" netmask="255.255.255.0">     <dhcp>       <range start="192.168.122.2" end="192.168.122.254" />     </dhcp>   </ip> </network> 2，再看一下虚拟机配置文件里面的网络设置 #cat /etc/libvirt/qemu/ubuntu10.04.xml <!-- WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE OVERWRITTEN AND LOST. Changes to this xml configuration should be made using:   virsh edit ubuntu10.04 or other application using the libvirt API. --> <domain type='kvm'>   <name>ubuntu10.04</name>   <uuid>2eeb1395-39a2-a169-4da3-f22b20a1d34f</uuid>   <memory unit='KiB'>1048576</memory>   <currentMemory unit='KiB'>1048576</currentMemory>   <vcpu placement='static'>1</vcpu>   <os>     <type arch='x86_64' machine='rhel6.3.0'>hvm</type>     <boot dev='hd'/>   </os>   <features>     <acpi/>     <apic/>     <pae/>   </features>   <clock offset='utc'/>   <on_poweroff>destroy</on_poweroff>   <on_reboot>restart</on_reboot>   <on_crash>restart</on_crash>   <devices>     <emulator>/usr/libexec/qemu-kvm</emulator>     <disk type='file' device='disk'>       <driver name='qemu' type='raw' cache='none'/>       <source file='/var/lib/libvirt/images/ubuntu10.04.img'/>       <target dev='vda' bus='virtio'/>       <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>     </disk>     <disk type='block' device='cdrom'>       <driver name='qemu' type='raw'/>       <target dev='hdc' bus='ide'/>       <readonly/>       <address type='drive' controller='0' bus='1' target='0' unit='0'/>     </disk>     <controller type='usb' index='0'>       <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>     </controller>     <controller type='ide' index='0'>       <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>     </controller>     <interface type='bridge'>   原来是interface type='default'       <mac address='52:54:00:50:58:7e'/>       <source bridge='br1'/>    原来是source network='default',这里的br1要根据你的物理网卡下面有讲       <model type='virtio'/>       <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>     </interface>     <serial type='pty'>       <target port='0'/>     </serial>     <console type='pty'>       <target type='serial' port='0'/>     </console>     <input type='mouse' bus='ps2'/>     <graphics type='vnc' port='-1' autoport='yes'/>     <sound model='ich6'>       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>     </sound>     <video>       <model type='cirrus' vram='9216' heads='1'/>       <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>     </video>     <memballoon model='virtio'>       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>     </memballoon>   </devices> </domain> 3，改完之后要更新一下配置文件 # virsh define ubuntu10.04.xml 定义域 ubuntu10.04（从 ubuntu10.04.xml） #然后就可以virsh start ubuntu10.04了，不过现在物理网卡这块还没有改好 4，物理网卡可以手动更改，不过现在有现成的工具包，可以用这个更改 #wget  http://www.convirture.com/downloads/convirture-tools/2.0.1/convirture-tools-2.0.1.tar.gz # tar zxvf convirture-tools-2.0.1.tar.gz # /root/convirture-tools/install/managed_server/scripts/convirt-tool --bridge setup 我的这里出现了点小问题，发现网络没起来，所以不要远程来做这个操作，主要原因是里面的配置文件有点需要 小的更改，我的是UUID注释了。 # ls ifcfg-* ifcfg-br1  ifcfg-br2  ifcfg-br3  ifcfg-br4  ifcfg-em1  ifcfg-em2  ifcfg-em3  ifcfg-em4  ifcfg-lo 我这里有四个物理网卡，所以生成了四个bridge,不过真实用的只有br1 这个工具好有一个好处就是保存了原配置文件，如果你不想用时还可以还原 # ls saved.ifcfg-em* saved.ifcfg-em1.20121128.101114  saved.ifcfg-em3.20121128.101114 saved.ifcfg-em2.20121128.101114  saved.ifcfg-em4.20121128.101114 看下ifceg-em1 # cat ifcfg-em1 DEVICE="em1" #BOOTPROTO=none NM_CONTROLLED="yes" ONBOOT=yes TYPE="Ethernet" #UUID="3bc7fdcc-42b1-4223-b202-e697305897c8" #IPADDR172.16.10.81 PREFIX=24 GATEWAY=172.16.10.254 DNS1=172.16.10.5 DEFROUTE=yes IPV4_FAILURE_FATAL=yes IPV6INIT=no NAME="System em1" HWADDR=90:B1:1C:20:4D:A5 BRIDGE=br1 看下ifcfg-br1 # cat ifcfg-br1 DEVICE="br1" BOOTPROTO=none NM_CONTROLLED="yes" ONBOOT=yes #UUID="3bc7fdcc-42b1-4223-b202-e697305897c8" IPADDR=172.16.10.81 PREFIX=24 GATEWAY=172.16.10.254 DNS1=172.16.10.5 DEFROUTE=yes IPV4_FAILURE_FATAL=yes IPV6INIT=no NAME="System br1" TYPE=Bridge 最后看下网卡 # ifconfig br1       Link encap:Ethernet  HWaddr 90:B1:1C:20:4D:A5            inet addr:172.16.10.81  Bcast:172.16.10.255  Mask:255.255.255.0           inet6 addr: fe80::92b1:1cff:fe20:4da5/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:10219 errors:0 dropped:0 overruns:0 frame:0           TX packets:3776 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:576031 (562.5 KiB)  TX bytes:15928008 (15.1 MiB) em1       Link encap:Ethernet  HWaddr 90:B1:1C:20:4D:A5            inet6 addr: fe80::92b1:1cff:fe20:4da5/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:10362 errors:0 dropped:0 overruns:0 frame:0           TX packets:13131 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000           RX bytes:766684 (748.7 KiB)  TX bytes:16489098 (15.7 MiB)           Interrupt:35 lo        Link encap:Local Loopback            inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:144411 errors:0 dropped:0 overruns:0 frame:0           TX packets:144411 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:147381248 (140.5 MiB)  TX bytes:147381248 (140.5 MiB) virbr0    Link encap:Ethernet  HWaddr 52:54:00:F1:6B:6E            inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:2028 errors:0 dropped:0 overruns:0 frame:0           TX packets:1135 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:233311 (227.8 KiB)  TX bytes:89372 (87.2 KiB) vnet0     Link encap:Ethernet  HWaddr FE:54:00:50:58:7E            inet6 addr: fe80::fc54:ff:fe50:587e/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:161 errors:0 dropped:0 overruns:0 frame:0           TX packets:3117 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:500           RX bytes:15533 (15.1 KiB)  TX bytes:263947 (257.7 KiB) vnet1     Link encap:Ethernet  HWaddr FE:54:00:B5:1A:19            inet6 addr: fe80::fc54:ff:feb5:1a19/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:56 errors:0 dropped:0 overruns:0 frame:0           TX packets:794 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:500           RX bytes:8754 (8.5 KiB)  TX bytes:42245 (41.2 KiB) 5,启动虚拟机ubuntu10.04后配置网卡 #cat /etc/network/interface auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 172.16.10.100 netmask 255.255.255.0 gateway 172.16.10.254 #/etc/init.d/networking restart 启动即可