虚拟化网络之OpenvSwitch(三)

上一篇介绍了openvswitch利用GRE协议，搭建多台宿主机的虚拟网络，接下来在利用vxlan通道搭建一个跨多宿主机的虚拟化网络，深入了解openvswitch的功能。一、实验拓扑

ip地址分配： A1：192.168.10.1/24 A2：192.168.10.10/24 B1：192.168.10.2/24 B2：192.168.10.20/24 eth1:10.10.10.1/24(图左) eth1:10.10.10.2/24(图右)操作系统： CentOS6.6x86_64
二、实验步骤 1)修改内核参数(一定要先修改内核参数，若果配置了网络名称空间在配置内核参数，内核参数将不会生效)

net.ipv4.ip_forward = 1 \\启用内核转发功能
net.ipv4.conf.all.rp_filter = 0  \\关闭路由验证
net.ipv4.conf.default.rp_filter = 0  \\关闭路由验证

# /etc/init.d/iptables stop  \\关闭防火墙
# setenforce 0 \\关闭Selinux

2)准备yum源

[openswitch]
name= openswitch
baseurl=https://repos.fedorapeople.org/openstack/EOL/openstack-icehouse/epel-6/
enabled=1
gpgcheck=0

3)安装openvswitch

# yum install openvswitch \\两台宿主机都要安装

4)启动openvswitch

# /etc/init.d/openvswitch start
Starting ovsdb-server                  [  OK  ] \\启动openvswitch数据库
Configuring Open vSwitch system IDs         [  OK  ] \\配置openvswitch的id
Starting ovs-vswitchd                 [  OK  ] \\启动openvswitch服务
Enabling remote OVSDB managers           [  OK  ] \\启用openvswitch的远程管理

5)更新iproute软件包，我们用来创建网络名称空间

# yum update iproute  \\更新iproute软件
# rpm -q iproute     \\查看更新之后的iproute软件是否带有netns后缀，如果没有，需要重新更新
iproute-2.6.32-130.el6ost.netns.2.x86_64

6)配置node3宿主机的虚拟网络

[root@node3 ~]# ip netns add A1  \\创建A1网络名称空间
[root@node3 ~]# ip netns add B1  \\创建B1网络名称空间
[root@node3 ~]# ip netns show    \\查看创建的玩两个名称空间
A1
B1
[root@node3 ~]# ovs-vsctl add-br br1  \\使用openvswitch创建br1桥设备
[root@node3 ~]# ovs-vsctl add-br br2  \\使用openvswitch创建br2桥设备
[root@node3 ~]# ovs-vsctl add-br br3  \\使用openvswitch创建br3桥设备
[root@node3 ~]# ovs-vsctl show   \\查看创建的桥设备
a6979a5b-bf54-48ac-b725-9beaa9be6c10
Bridge "br2"
Port "br2"
Interface "br2"
type: internal
Bridge "br1"
Port "br1"
Interface "br1"
type: internal
Bridge "br3"
Port "br3"
Interface "br3"
type: internal
ovs_version: "2.1.3"
[root@node3 ~]# ip link add name a1.1 type veth peer name a1.2 \\创建一对端口，用于连接A1网络名称空间跟br2桥设备
[root@node3 ~]# ip link set a1.1 up  \\激活a1.1端口
[root@node3 ~]# ip link set a1.2 up   \\激活a1.2端口
[root@node3 ~]# ip link add name b1.1 type veth peer name b1.2 \\创建一对端口，用于连接B1网络名称空间与br3桥设备
[root@node3 ~]# ip link set b1.2 up   \\激活b1.2端口
[root@node3 ~]# ip link set b1.1 up   \\激活b1.1端口
[root@node3 ~]# ip link add name b12.1 type veth peer name b12.2  \\创建一对端口，用于连接br2与br1桥设备
[root@node3 ~]# ip link set b12.1 up  \\激活b12.1端口
[root@node3 ~]# ip link set b12.2 up   \\激活b12.2端口
[root@node3 ~]# ip link add name b13.1 type veth peer name b13.2 \\创建一对端口，用于连接br3与br1桥设备
[root@node3 ~]# ip link set b13.1 up  \\激活b13.1端口
[root@node3 ~]# ip link set b13.2 up   \\激活b13.2端口
[root@node3 ~]# ip link add name b23.1 type veth peer name b23.2 \\创建一对端口，用于连接br2与br3桥设备
[root@node3 ~]# ip link set b23.1 up  \\激活b23.1端口
[root@node3 ~]# ip link set b23.2 up   \\激活b23.2端口
[root@node3 ~]# ovs-vsctl add-port br2 a1.1  \\把a1.2端口加入到br2桥设备上
[root@node3 ~]# ip link set a1.2 netns A1  \\把a1.2端口添加到A1网络名称空间，要注意，a1.2添加到网络名称空间后不会再本地显示
[root@node3 ~]# ovs-vsctl add-port br3 b1.1  \\把b1.1端口加入到br3桥设备上
[root@node3 ~]# ip link set b1.2 netns B1    \\把b1.2端口加入到B1网络名称空间
[root@node3 ~]# ovs-vsctl add-port br2 b23.2     \\把b23.2端口加入到br2桥设备上
[root@node3 ~]# ovs-vsctl add-port br3 b23.1     \\把b23.1加入到br3桥设备上
[root@node3 ~]# ip netns exec A1  ip link set a1.2 up    \\把添加到A1网络名称空间的网卡激活
[root@node3 ~]# ip netns exec A1  ip addr add 192.168.10.1/24 dev a1.2  \\给A1网络名称空间配置一个ip地址
[root@node3 ~]# ip netns exec A1 ifconfig \\查看配置的ip地址
a1.2      Link encap:Ethernet  HWaddr 2A:1F:79:47:7D:DC
inet addr:192.168.10.1  Bcast:0.0.0.0  Mask:255.255.255.0
inet6 addr: fe80::281f:79ff:fe47:7ddc/64 Scope:Link
UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:468 (468.0 b)  TX bytes:936 (936.0 b)
[root@node3 ~]# ip netns exec B1 ip link set b1.2 up    \\把添加到B1网络名称空间的端口激活
[root@node3 ~]# ip netns exec B1 ip addr add 192.168.10.2/24 dev b1.2 \\激活之后配置ip地址
[root@node3 ~]# ip netns exec B1 ifconfig    \\查看配置的ip地址
b1.2      Link encap:Ethernet  HWaddr BA:E8:B0:20:1C:05
inet addr:192.168.10.2  Bcast:0.0.0.0  Mask:255.255.255.0
inet6 addr: fe80::b8e8:b0ff:fe20:1c05/64 Scope:Link
UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:468 (468.0 b)  TX bytes:936 (936.0 b)
[root@node3 ~]# ip netns exec B1  ping 192.168.10.1  \\在B1网络名称空间可以ping通A1网络名称空间
PING 192.168.10.1 (192.168.10.1) 56(84) bytes of data.
64 bytes from 192.168.10.1: icmp_seq=1 ttl=64 time=2.66 ms
64 bytes from 192.168.10.1: icmp_seq=2 ttl=64 time=0.051 ms
64 bytes from 192.168.10.1: icmp_seq=3 ttl=64 time=0.054 ms
[root@node3 ~]# ip netns exec A1  ping 192.168.10.2   \\在A1网络名称空间可以ping通B1网络名称空间
PING 192.168.10.2 (192.168.10.2) 56(84) bytes of data.
64 bytes from 192.168.10.2: icmp_seq=1 ttl=64 time=1.52 ms
64 bytes from 192.168.10.2: icmp_seq=2 ttl=64 time=0.075 ms
[root@node3 ~]# ovs-vsctl add-port br1 b12.2    \\添加b12.2端口到br1桥设备上
[root@node3 ~]# ovs-vsctl add-port br1 b13.2     \\添加b13.2端口到br1桥设备上
[root@node3 ~]# ovs-vsctl add-port br2 b12.1      \\添加b12.1端口到br2桥设备上
[root@node3 ~]# ovs-vsctl add-port br3 b13.1       \\添加b13.1端口到br3桥设备上
[root@node3 ~]# ovs-vsctl set Bridge br1 stp_enable=true \\为了防止br1、br2、br3桥设备产生环路，开启stp协议
[root@node3 ~]# ovs-vsctl set Bridge br2 stp_enable=true  \\为了防止br1、br2、br3桥设备产生环路，开启stp协议
[root@node3 ~]# ovs-vsctl set Bridge br3 stp_enable=true   \\为了防止br1、br2、br3桥设备产生环路，开启stp协议

7)配置node4宿主机的虚拟网络

修改内核信息
net.ipv4.ip_forward = 1
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.all.rp_filter = 0

# /etc/init.d/iptables stop  \\关闭防火墙
# setenforce 0    \\关闭SElinux

创建网桥
[root@node4 ~]# ovs-vsctl add-br br1
[root@node4 ~]# ovs-vsctl add-br br2
[root@node4 ~]# ovs-vsctl add-br br3

创建网络名称空间
[root@node4 ~]# ip netns add A2
[root@node4 ~]# ip netns add B2

创建多对端口，用于连接桥设备与网络名称空间的互联
[root@node4 ~]# ip link add a1.1 type veth peer name a1.2
[root@node4 ~]# ip link set a1.1 up
[root@node4 ~]# ip link set a1.2 up
[root@node4 ~]# ip link add b1.1 type veth peer name b1.2
[root@node4 ~]# ip link set b1.1 up
[root@node4 ~]# ip link set b1.2 up
[root@node4 ~]# ip link add b12.1 type veth peer name b12.2
[root@node4 ~]# ip link set b12.1 up
[root@node4 ~]# ip link set b12.2 up
[root@node4 ~]# ip link add b13.1 type veth peer name b13.2
[root@node4 ~]# ip link set b13.1 up
[root@node4 ~]# ip link set b13.2 up
[root@node4 ~]# ip link add name b23.1 type veth peer name b23.2
[root@node4 ~]# ip link set b23.1 up
[root@node4 ~]# ip link set b23.2 up

配置br2与A2网络名称空间互联
[root@node4 ~]# ip link set a1.1 netns A2
[root@node4 ~]# ovs-vsctl add-port br2 a1.2

配置br3与B2网络名称空间互联
[root@node4 ~]# ip link set b1.1 netns B2
[root@node4 ~]# ovs-vsctl add-port br3 b1.2

配置br2与br3桥设备互联
[root@node4 ~]# ovs-vsctl add-port br2 b23.1
[root@node4 ~]# ovs-vsctl add-port br3 b23.2

配置A2网络名称空间的ip地址
[root@node4 ~]# ip netns exec A2 ip link set a1.1 up
[root@node4 ~]# ip netns exec A2 ip addr add 192.168.10.10/24 dev a1.1

配置B2网络名称空间的ip地址
[root@node4 ~]# ip netns exec B2  ip link set b1.1 up
[root@node4 ~]# ip netns exec B2 ip addr add 192.168.10.20/24 dev b1.1

测试A2与B2网络名称空间的连通性
[root@node4 ~]# ip netns exec B2 ping 192.168.10.10
PING 192.168.10.10 (192.168.10.10) 56(84) bytes of data.
64 bytes from 192.168.10.10: icmp_seq=1 ttl=64 time=1.68 ms
64 bytes from 192.168.10.10: icmp_seq=2 ttl=64 time=0.065 ms

[root@node4 ~]# ip netns exec A2 ping 192.168.10.20
PING 192.168.10.20 (192.168.10.20) 56(84) bytes of data.
64 bytes from 192.168.10.20: icmp_seq=1 ttl=64 time=2.80 ms
64 bytes from 192.168.10.20: icmp_seq=2 ttl=64 time=0.048 ms

配置br2与br1桥设备互联
[root@node4 ~]# ovs-vsctl add-port br1 b12.1
[root@node4 ~]# ovs-vsctl add-port br2 b12.2

配置br3与br1桥设备互联
[root@node4 ~]# ovs-vsctl add-port br1 b13.1
[root@node4 ~]# ovs-vsctl add-port br3 b13.2

为了防止桥设备产生环路，在桥设备上开启stp协议
[root@node4 ~]# ovs-vsctl set Bridge br1 stp_enable=true
[root@node4 ~]# ovs-vsctl set Bridge br2 stp_enable=true
[root@node4 ~]# ovs-vsctl set Bridge br3 stp_enable=true

8)配置VXLAN通道

先配置用于建立vxlan通道的eth1网卡接口的ip地址
[root@node3 ~]# ifconfig eth1 10.10.10.1/24 up
[root@node4 ~]# ifconfig eth1 10.10.10.2/24 up

测试连通性
[root@node3 ~]# ping 10.10.10.1
PING 10.10.10.1 (10.10.10.1) 56(84) bytes of data.
64 bytes from 10.10.10.1: icmp_seq=1 ttl=64 time=0.066 ms

[root@node4 ~]# ping 10.10.10.1
PING 10.10.10.1 (10.10.10.1) 56(84) bytes of data.
64 bytes from 10.10.10.1: icmp_seq=1 ttl=64 time=2.94 ms
64 bytes from 10.10.10.1: icmp_seq=2 ttl=64 time=0.305 ms

分别在两台宿主机的br1桥设备上添加一个用于vxlan封装的端口
[root@node3 ~]# ovs-vsctl add-port br1 vxlan
[root@node4 ~]# ovs-vsctl add-port br1 vxlan

更改添加vxlan端口的封装属性
[root@node3 ~]# ovs-vsctl  set Interface vxlan type=vxlan  options:remote_ip=10.10.10.2
[root@node4 ~]# ovs-vsctl set Interface vxlan type=vxlan options:remote_ip=10.10.10.1

测试两台宿主机之间网络名称空间的连通性
在node3宿主上测试
[root@node3 ~]# ip  netns exec A1 ping 192.168.10.2
PING 192.168.10.2 (192.168.10.2) 56(84) bytes of data.
64 bytes from 192.168.10.2: icmp_seq=1 ttl=64 time=2.30 ms
^C
--- 192.168.10.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 917ms
rtt min/avg/max/mdev = 2.306/2.306/2.306/0.000 ms
[root@node3 ~]# ip  netns exec A1 ping 192.168.10.10
PING 192.168.10.10 (192.168.10.10) 56(84) bytes of data.
64 bytes from 192.168.10.10: icmp_seq=1 ttl=64 time=3.66 ms
64 bytes from 192.168.10.10: icmp_seq=2 ttl=64 time=0.759 ms
^C
--- 192.168.10.10 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1263ms
rtt min/avg/max/mdev = 0.759/2.211/3.664/1.453 ms

[root@node3 ~]# ip  netns exec A1 ping 192.168.10.20
PING 192.168.10.20 (192.168.10.20) 56(84) bytes of data.
64 bytes from 192.168.10.20: icmp_seq=1 ttl=64 time=4.79 ms
64 bytes from 192.168.10.20: icmp_seq=2 ttl=64 time=0.442 ms
^C
--- 192.168.10.20 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1285ms
rtt min/avg/max/mdev = 0.442/2.619/4.797/2.178 ms

在node4宿主机上测试
[root@node4 ~]# ip netns exec A2 ping 192.168.10.1
PING 192.168.10.1 (192.168.10.1) 56(84) bytes of data.
64 bytes from 192.168.10.1: icmp_seq=1 ttl=64 time=6.75 ms
64 bytes from 192.168.10.1: icmp_seq=2 ttl=64 time=1.53 ms
^C
--- 192.168.10.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1376ms
rtt min/avg/max/mdev = 1.536/4.146/6.756/2.610 ms
[root@node4 ~]# ip netns exec A2 ping 192.168.10.3
PING 192.168.10.3 (192.168.10.3) 56(84) bytes of data.
^C
--- 192.168.10.3 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1381ms

[root@node4 ~]# ip netns exec A2 ping 192.168.10.2
PING 192.168.10.2 (192.168.10.2) 56(84) bytes of data.
64 bytes from 192.168.10.2: icmp_seq=1 ttl=64 time=5.68 ms
^C
--- 192.168.10.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 769ms
rtt min/avg/max/mdev = 5.680/5.680/5.680/0.000 ms
[root@node4 ~]# ip netns exec A2 ping 192.168.10.20
PING 192.168.10.20 (192.168.10.20) 56(84) bytes of data.
64 bytes from 192.168.10.20: icmp_seq=1 ttl=64 time=2.50 ms
^C
--- 192.168.10.20 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 913ms
rtt min/avg/max/mdev = 2.502/2.502/2.502/0.000 ms

在node4宿主机上ping  node3宿主机上的网络名称空间，在node3宿主机上抓包分析
[root@node3 ~]# tcpdump -nn -i eth1
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
10:34:12.799191 IP 10.10.10.1.58588 > 10.10.10.2.4789: UDP, length 60
10:34:13.578197 IP 10.10.10.2.56807 > 10.10.10.1.4789: UDP, length 106
10:34:13.578264 IP 10.10.10.1.38137 > 10.10.10.2.4789: UDP, length 106
通过以上数据分析，可以发现vxlan利用udp封装数据报文将两台宿主机之前的虚拟网络打通

[root@node3 ~]# ip netns exec A1 tcpdump -nn  icmp    -i a1.2
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on a1.2, link-type EN10MB (Ethernet), capture size 65535 bytes
10:35:33.692847 IP 192.168.10.10 > 192.168.10.1: ICMP echo request, id 42539, seq 93, length 64
10:35:33.692875 IP 192.168.10.1 > 192.168.10.10: ICMP echo reply, id 42539, seq 93, length 64
10:35:34.693605 IP 192.168.10.10 > 192.168.10.1: ICMP echo request, id 42539, seq 94, length 64
通过以上抓包数据分析，可以看出A1与A2之间的通信信息

9)到此实验已经结束，两台宿主机之前的虚拟网络搭建完成

关于GRE协议，大家可以参考以下链接，这里就不在详细讲述了：http://www.tuicool.com/articles/zyiuIzUhttp://www.tuicool.com/articles/6zMJRn