繼上文《Ubuntu14.04安裝配置Open vSwitch》安裝好Open vSwitch后，這里我們將要創建兩個KVM虛擬機，並通過DNSmasq來為這兩個虛擬機自動分配私網IP地址。
虛擬機與宿主機網絡結構圖大致如下所示：
測試環境說明：
1）測試私網段：172.17.0.0/24
2）測試 vlan tag：100
下面簡要介紹下整個配置流程：
1、安裝dnsmasq：
◄► sudo apt-get install dnsmasq Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: dnsmasq 0 upgraded, 1 newly installed, 0 to remove and 37 not upgraded. Need to get 14.9 kB of archives. After this operation, 114 kB of additional disk space will be used. Get:1 http://cn.archive.ubuntu.com/ubuntu/ trusty-updates/universe dnsmasq all 2.68-1ubuntu0.1 [14.9 kB] Fetched 14.9 kB in 0s (138 kB/s) Selecting previously unselected package dnsmasq. (Reading database ... 231198 files and directories currently installed.) Preparing to unpack .../dnsmasq_2.68-1ubuntu0.1_all.deb ... Unpacking dnsmasq (2.68-1ubuntu0.1) ... Processing triggers for ureadahead (0.100.0-16) ... ureadahead will be reprofiled on next reboot Setting up dnsmasq (2.68-1ubuntu0.1) ... * Starting DNS forwarder and DHCP server dnsmasq [ OK ] Processing triggers for ureadahead (0.100.0-16) ... ◄► sudo ps -ea | grep dns 3307 ? 00:00:00 dnsmasq
2、通過 ovs 創建一個 internal port，這里取名為 qdhcp，並設置 vlan id 為100，供下文的 dnsmasq 進程使用：
◄► sudo ovs-vsctl add-port br0 qdhcp tag=100 ◄► sudo ovs-vsctl set Interface qdhcp type=internal
3、查看已經創建的 qdhcp port：
◄► sudo ovs-vsctl show 1e6548a9-956e-4b86-b743-f8da0aa2b922 Bridge "br0" Port "br0" Interface "br0" type: internal Port qdhcp tag: 100 Interface qdhcp type: internal Port "eth0" Interface "eth0" ovs_version: "2.0.2" ◄► ifconfig qdhcp Link encap:Ethernet HWaddr 72:6c:a8:c2:48:68 inet6 addr: fe80::706c:a8ff:fec2:4868/64 Scope:Link UP BROADCAST RUNNING MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:7 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:578 (578.0 B)
4、給 qdhcp 虛擬網卡配置 IP 地址，這里IP地址必須為測試私網內的，這里我們就分配 172.17.0.1 給qdhcp：
◄► sudo ifconfig qdhcp 172.17.0.1 netmask 255.255.255.0 up ◄► ifconfig qdhcp Link encap:Ethernet HWaddr 72:6c:a8:c2:48:68 inet addr:172.17.0.1 Bcast:172.17.0.255 Mask:255.255.255.0 inet6 addr: fe80::706c:a8ff:fec2:4868/64 Scope:Link UP BROADCAST RUNNING MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:8 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:648 (648.0 B)
5、啟動一個 dnsmasq 進程，監聽 qdhcp 虛擬網卡：
◄► sudo /usr/sbin/dnsmasq --strict-order --bind-interfaces --interface=qdhcp --except-interface=lo --pid-file=/var/run/dnsmasq/qdhcp.pid --leasefile-ro --dhcp-range=172.17.0.2,172.17.0.254,255.255.255.0,12h --conf-file=
6、查看已經啟動的 dnsmasq 進程：
◄► ps aux | grep dnsmasq nobody 3471 0.0 0.0 35228 2412 ? S 12:26 0:00 /usr/sbin/dnsmasq --strict-order --bind-interfaces --interface=qdhcp --except-interface=lo --pid-file=/var/run/dnsmasq/qdhcp.pid --leasefile-ro --dhcp-range=172.17.0.2,172.17.0.254,255.255.255.0,12h --conf-file=
7、下面就是整理兩個虛擬機VM1、VM2的配置文件，這里僅展示 interface 這塊配置項：
VM1：
<interface type='bridge'> <source bridge='br0'/> <vlan> <tag id='100'/> </vlan> <virtualport type='openvswitch'/> <target dev='tap0'/> <model type='virtio'/> </interface> VM2： <interface type='bridge'> <source bridge='br0'/> <vlan> <tag id='100'/> </vlan> <virtualport type='openvswitch'/> <target dev='tap0'/> <model type='virtio'/> </interface>
這里將兩個虛擬機的虛擬網卡的 vlan id 都設為 100，即必須保證和 qdhcp port在同一個vlan中。
8、啟動VM1、VM2，並查看 ovs 虛擬網卡 tap0、tap1 的情況：
◄► sudo ovs-vsctl show 1e6548a9-956e-4b86-b743-f8da0aa2b922 Bridge "br0" Port "tap1" tag: 100 Interface "tap1" Port "br0" Interface "br0" type: internal Port qdhcp tag: 100 Interface qdhcp type: internal Port "eth0" Interface "eth0" Port "tap0" tag: 100 Interface "tap0" ovs_version: "2.0.2"
由此，我們已經將VM1、VM2和qdhcp port分在了同一個VLAN里了。
10、通過VNC登陸到VM1、VM2中，查看其是否獲取到指定私網段IP地址：
VM1：
VM2：
11、從VM1 ping VM2：
至此，整合Open vSwitch與DNSmasq的功能就完成了，兩個虛擬機之間就可以愉快地玩耍了。