4个节点：

　　keepalived1:

　　　　IP:172.16.20.10

　　　　hostname:knode1.lushenle.com

　　　　OS:CentOS Linux release 7.1.1503 (Core)

　　　　NetworkDEVICE:eno16777728

　　keepalived2:

　　　　IP:172.16.20.12

　　　　hostname:knode2.lushenle.com

　　　　OS:CentOS Linux release 7.1.1503 (Core)

　　　　NetworkDEVICE:eno16777728

　　Real Server1:

　　　　IP:172.16.100.40

　　　　hostname:node1.lushenle.com

　　　　OS:CentOS Linux release 7.4.1708 (Core)

　　　　NetworkDEVICE:ens32

　　Real Server2:

　　　　IP:172.16.100.50

　　　　hostname:node3.lushenle.com

　　　　OS:CentOS Linux release 7.4.1708 (Core)

　　　　NetworkDEVICE:ens32

　　还有一个节点是客户端，IP地址为172.16.100.20，OS为MacOSX。其中Real Server2还是yum源。VIP为172.16.20.100，各节点之间的都能相互解析主机名，使用了公钥认证

　　两个keepalived节点开启核心转发功能，操作是在keepalived1节点中完成的：

　　　　# echo 1 > /proc/sys/net/ipv4/ip_forward; ssh knode2.lushenle.com 'echo 1 > /proc/sys/net/ipv4/ip_forward'

　　安装keepalived，ipvsadm，httpd，其中httpd的作用是Sorry_server:

　　　　# yum install -y keepalived，ipvsadm，httpd; ssh knode2.lushenle.com 'yum install -y keepalived，ipvsadm，httpd'

　　　　# echo "<h1>The system is upgrading on knode1 Please wait a few minutes retry!<h1>" > /var/www/html/index.html

　　keepalived2也是一样的，但为了测试效果，加以区别，可显示不同的内容

　　　　# echo "<h1>The system is upgrading on knode2 Please wait a few minutes retry!<h1>" > /var/www/html/index.html

　　　　# systemctl start http; ssh knode2.lushenle.com 'systemctl start http'

　　配置keepalived，在不停止服务的前提下可以通过脚本的方式进行流转，且流转的时候发邮件：

　　　　# cp /etc/keepalived/keepalived.conf{,.bak} ```先备份一下```

　　　　# vim /etc/keepalived/keepalived.conf

1 ! Configuration File for keepalived 2  3 global_defs { 4     notification_email { 5     root@localhost 6     } 7     notification_email_from kaadmin@localhost 8     smtp_server 127.0.0.1 9     smtp_connect_timeout 3010     router_id LVS_DEVEL11     vrrp_mcast_group4 224.0.1.11812 }13 14 vrrp_script chk_down {15     script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"16     interval 117     weight -2018 }19 20 vrrp_instance VI_1 {21     state MASTER22     interface eno1677772823     virtual_router_id 14424     priority 10025     advert_int 126     authentication {27         auth_type PASS28         auth_pass 44dace615cdd5d26 29     }30     virtual_ipaddress {31     172.16.20.100/16 dev eno16777728 label eno16777728:132     }33             34     track_script {35         chk_down36     }37             38     notify_master "/etc/keepalived/notify.sh master"39     notify_backup "/etc/keepalived/notify.sh backup"40     notify_fault "/etc/keepalived/notify.sh fault"41 }42 43 virtual_server 172.16.20.100 80 {44     delay_loop 645     lb_algo wrr46     lb_kind DR47     nat_mask 255.255.0.048     protocol TCP49     sorry_server 127.0.0.1 8050 51     real_server 172.16.100.40 80 {52         weight 153         HTTP_GET {54             url {55               path /56               status_code 200 57             }58             connect_timeout 359             nb_get_retry 360             delay_before_retry 361         }62     }63     real_server 172.16.100.50 80 {64         weight 265         HTTP_GET {66             url {67                path /68                status_code 200 69             }70             connect_timeout 371             nb_get_retry 372             delay_before_retry 373         }74     }75 }

　　将keepalived1节点中/etc/keepalived/keepalived.conf文件复制keepalived2节点中，将state MASTER改为state BACKUP，priority 100改为priority 90即可

　　　　# vim /etc/keepalived/notify.sh

1 #!/bin/bash 2 # 3  4 vip=172.16.20.100 5 contact='root@localhost' 6  7 notify() { 8     mailsubject="`hostname` to be $1: $vip floating" 9     mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"10     echo $mailbody | mail -s "$mailsubject" $contact11 }12 13 case "$1" in14     master)15         notify master16         exit 017     ;;18     backup)19         notify backup20         exit 021     ;;22     fault)23         notify fault24         exit 025     ;;26     *)27         echo 'Usage: `basename $0` {master|backup|fault}'28         exit 129     ;;30 esac

　　也将此脚本复制到keepalived2节点中

　　启动两个keepalived节点：

　　　　# systemctl start keepalived; ssh knode2.lushenle.com 'systemctl start keepalived'

　　　　此时可查看自动生成的ipvs规则

　　　　　　# ipvsadm -L -n

　　两台Real Server中修改内核参数，将Real Server中VIP配置在ens32网卡的别名ens32:0上，并限制其不能响应对VIP地址的请求：

　　　　# vim set.sh

1 #!/bin/bash2 #3 vip=172.16.20.1004 ifconfig ens32:0 $vip broadcast $vip netmask 255.255.255.255 up5 route add -host $vip ens32:06 echo 1 > /proc/sys/net/ipv4/conf/ens32/arp_ignore7 echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore8 echo 2 > /proc/sys/net/ipv4/conf/ens32/arp_announce9 echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce

　　为Real Server1提供内容，因为Real Server2位所有节点的yum源，就懒得去修改了：

　　　　# echo "<h1>This is on real server1<h1>" > /var/www/html/index.html

　　启动两个Real Server的服务：

　　　　# systemctl start httpd; ssh node3.lushenle.com 'systemctl start httpd'

　　客户端进行访问、测试