一、环境说明：
操作系统：Centos-6.5_x86_64
keepalived软件安装在node2和node3机器上。
实际安装之前，先关闭keepalived节点（node2,node3）上的防火墙。
[root@node2 ~]# service iptables stop
二、软件安装：
这里需要安装的软件是keepalived。node2和node3都需要安装。
[root@node2 ~]# yum install keepalived
安装完毕后，配置文件在/etc/keepalived/keepalived.conf下。
三、配置文件：
1、MASTER配置文件（node2）：
! Configuration File for keepalived
bal_defs {
notification_email {
root@localhost
}
notification_email_from laoxiao@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.103.100/24 dev eth0 label eth0:1
}
}
virtual_server 192.168.103.100 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.103.101 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.103.105 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}2、BACKUP配置文件（node3）：
! Configuration File for keepalived
bal_defs {
notification_email {
root@localhost
}
notification_email_from laoxiao@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 50
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.103.100/24 dev eth0 label eth0:1
}
}
virtual_server 192.168.103.100 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.103.101 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.103.105 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}四、测试：
1、首先分别启动node2和node3上的keepalived服务：
[root@node2 ~]# service keepalived start
[root@node3 ~]# service keepalived start
启动时产生的日志在/var/log/messages文件中，可以观察其中的日志。MASTER效果如下：BACKUP会略有不同。
2、查看node2(MASTER)中的状态：
[root@node2 ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:CE:06:D7
inet addr:192.168.103.102 Bcast:192.168.103.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fece:6d7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11485 errors:0 dropped:0 overruns:0 frame:0
TX packets:33202 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2217383 (2.1 MiB) TX bytes:2537512 (2.4 MiB) eth0:1 Link encap:Ethernet HWaddr 00:0C:29:CE:06:D7
inet addr:192.168.103.100 Bcast:0.0.0.0 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 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)
[root@node2 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.103.100:80 wrr persistent 50
-> 192.168.103.101:80 Route 1 0 0
-> 192.168.103.105:80 Route 1 0 0
上述可以看到MASTER中的网卡是启用的。
3、查看BACKUP(node3)上的状态：
[root@node3 keepalived]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:BE:D3:CA
inet addr:192.168.103.103 Bcast:192.168.103.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:febe:d3ca/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:249981 errors:0 dropped:0 overruns:0 frame:0
TX packets:72173 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:284573915 (271.3 MiB) TX bytes:5287459 (5.0 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:1898 errors:0 dropped:0 overruns:0 frame:0
TX packets:1898 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:229406 (224.0 KiB) TX bytes:229406 (224.0 KiB)
[root@node3 keepalived]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.103.100:80 wrr persistent 50
-> 192.168.103.101:80 Route 1 0 0
-> 192.168.103.105:80 Route 1 0 0
如果node3没有关闭防火墙的话，也会启用eth0:1网卡，所以注意将防火墙关闭。