今天來看一下LVS的第三種模式IP TUN。

TUN方式，是通過給數據包加上新的IP頭部來實現，這個可以跨整個廣域網。

環境：

分發器：
1、配置網絡：

ens33 192.168.199.7 DIP

ens33:1 192.168.199.63 VIP

[root@openstack ~]#ifconfig ens33:1 192.168.199.63 netmask 255.255.255.0 up

[root@openstack ~]# echo 1 > /proc/sys/net/ipv4/ip_forward 開啟路由轉發功能

2、配置IP TUN模式

root@openstack ~]#yum install ipvsadm -y

[root@openstack ~]#ipvsadm -A -t 192.168.199.63:80 -s rr
[root@openstack ~]#ipvsadm -a -t 192.168.199.63:80 -r 192.168.199.11:80 -i #-i隧道模式
[root@openstack ~]#ipvsadm -a -t 192.168.199.63:80 -r 192.168.199.12:80 -i

[root@openstack ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.199.63:80 rr
-> 192.168.199.11:80 Tunnel 1 0 0
-> 192.168.199.12:80 Tunnel 1 0 0

Realserver1：tiandong63

1、配置網絡：

eth0 RIP：192.168.199.11

[root@tiandong63 ~]# modprobe ipip #在加載好ipip模塊後就會有默認的tunl0隧道。

[root@tiandong63 ~]# lsmod |grep ipip
ipip 8371 0
tunnel4 2943 1 ipip

[root@tiandong63 ~]#ifconfig tunl0 192.168.199.63 netmask 255.255.255.255 up

[root@tiandong63 ~]# service network restart

[root@tiandong63 ~]# ifconfig -a 此時就可以看到tunl0的網卡了。
eth0 Link encap:Ethernet HWaddr 00:0C:29:38:0B:14
inet addr:192.168.199.11 Bcast:192.168.199.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe38:b14/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:113954 errors:0 dropped:0 overruns:0 frame:0
TX packets:40448 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:164480499 (156.8 MiB) TX bytes:2794350 (2.6 MiB)

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:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

tunl0 Link encap:IPIP Tunnel HWaddr
inet addr:192.168.199.63 Mask:255.255.255.255
UP RUNNING NOARP MTU:1480 Metric:1
RX packets:20 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1664 (1.6 KiB) TX bytes:0 (0.0 b)

2、關閉ARP轉發：

[root@tiandong63 ~]# vim /etc/sysctl.conf 在最後加上：
net.ipv4.conf.tunl0.arp_ignore = 1
net.ipv4.conf.tunl0.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.tunl0.rp_filter = 0
net.ipv4.conf.all.rp_filter = 0

[root@tiandong63 ~]# sysctl -p 是配置生效
3、配置web服務器

[root@tiandong63 ~]#yum install httpd -y

[root@tiandong63 ~]# echo ‘this is 192.168.199.11‘ > /var/www/html/index.html 寫一個測試頁面
[root@tiandong63 ~]# /etc/init.d/httpd start

Realserver2：tiandong64

1、配置網絡

eth0 RIP：192.168.199.12

[root@tiandong64 ~]# modprobe ipip
[root@tiandong64 ~]# lsmod |grep ipip
ipip 8371 0
tunnel4 2943 1 ipip

[root@tiandong64 ~]#ifconfig tunl0 192.168.199.63 netmask 255.255.255.255 up

[root@tiandong64 ~]# service network restart

[root@tiandong64 ~]# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:0C:29:C7:20:71
inet addr:192.168.199.12 Bcast:192.168.199.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fec7:2071/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:41108 errors:0 dropped:0 overruns:0 frame:0
TX packets:13848 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:57855802 (55.1 MiB) TX bytes:884097 (863.3 KiB)

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:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

tunl0 Link encap:IPIP Tunnel HWaddr
inet addr:192.168.199.63 Mask:255.255.255.255
UP RUNNING NOARP MTU:1480 Metric:1
RX packets:25 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2080 (2.0 KiB) TX bytes:0 (0.0 b)

2、關閉ARP轉發：

[root@tiandong64 ~]# vim /etc/sysctl.conf 在最後加上：
net.ipv4.conf.tunl0.arp_ignore = 1
net.ipv4.conf.tunl0.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.tunl0.rp_filter = 0
net.ipv4.conf.all.rp_filter = 0

[root@tiandong64 ~]# sysctl -p 是配置生效
3、配置web服務器

[root@tiandong64 ~]#yum install httpd -y

[root@tiandong64 ~]# echo ‘this is 192.168.199.12‘ > /var/www/html/index.html 寫一個測試頁面
[root@tiandong64 ~]# /etc/init.d/httpd start

然後進行測試：

[root@localhost ~]#yum install elinks -y

[root@localhost ~]# elinks 192.168.199.63 --dump
this is 192.168.199.11
[root@localhost ~]# elinks 192.168.199.63 --dump
this is 192.168.199.12
[root@localhost ~]# elinks 192.168.199.63 --dump
this is 192.168.199.11
[root@localhost ~]# elinks 192.168.199.63 --dump
this is 192.168.199.12
在分發器上查看： 是平均分配的。

[root@openstack ~]# ipvsadm -ln --stats
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Conns InPkts OutPkts InBytes OutBytes
-> RemoteAddress:Port
TCP 192.168.199.63:80 4 20 0 1664 0
-> 192.168.199.11:80 2 10 0 832 0
-> 192.168.199.12:80 2 10 0 832 0

LVS集群之IP TUN模式