keepalived+lvs子网掩码造成VIP切换故障 + vrrp_script+track_script

keepalived+lvs子网掩码造成VIP切换故障
架构：keepalived+lvs ，前端调度器是双主模型
现象：keepalived手动停掉一台，但是虚拟IP不会切换

整体网络是24位
VIP：172.18.3.200
keepalived的路由
[root@Sserver3- clouder]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.18.3.1      0.0.0.0         UG                   eth0
169.254.0.0     0.0.0.0         255.255.0.0     U                 eth0
172.18.0.0      0.0.0.0         255.255.0.0     U                    eth0
172.18.3.0      0.0.0.0         255.255.255.0   U                    eth0

PS：不fail over 原因就是这条16位的路由作怪
: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc pfifo_fast state UP qlen
    link/ether :cf::::3b brd ff:ff:ff:ff:ff:ff
    inet 172.18.3.53/ brd 172.18.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 172.18.3.200/ scope global eth0  #没有secondary
       valid_lft forever preferred_lft forever
    inet 172.18.3.201/ scope global secondary eth0
       valid_lft forever preferred_lft forever

解决，配置检查：
后端realserver配置的虚拟IP为：
/sbin/ifconfig lo: 172.18.3.200 broadcast 172.18.3.200 netmask 255.255.255.255 up
/sbin/route add -host 172.18.3.200 dev lo:

前端keepalived：
virtual_ipaddress {
      172.18.3.200/
 }
明显子网掩码出问题了。
virtual_ipaddress {
      172.18.3.200/
}

重启keepalived，检查现象：
[root@Sserver3- clouder]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.18.3.1      0.0.0.0         UG                   eth0
169.254.0.0     0.0.0.0         255.255.0.0     U                 eth0
172.18.3.0      0.0.0.0         255.255.255.0   U                    eth0

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc pfifo_fast state UP qlen
    link/ether :cf::::3b brd ff:ff:ff:ff:ff:ff
    inet 172.18.3.53/ brd 172.18.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 172.18.3.200/ scope global secondary eth0
       valid_lft forever preferred_lft forever

15.2    keepalived在centos7.2中的bug
keepalived 在centos7. 使用 /bin/systemctl restart keepalived.service 配置文件没有生效
需要使用reload参数来重新生效

参考：

https://www.cnblogs.com/paul8339/p/9644821.html

Keepalived详解（四）：通过vrrp_script实现对集群资源的监控【转】