LVS,DR模式+Keepalived部署

配置信息

LVS-MASTER	10.0.0.41	centos7
LVS-BACKUP	10.0.0.42	centos7
LVS-DR-VIP	10.0.0.100
WEB1	10.0.0.43	centos7
WEB2	10.0.0.44	centos7

注意：请忽略IP地址，以自己环境中的为主。
一、配置LVS
1.分别在master和backup上安装lvs和keepalived软件包

systemctl stop firewalld
setenforce 0
yum –y install keepalived ipvsadm

LVS-MASTER

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id LVS_R1
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33  #对应网卡
    virtual_router_id 51
    priority 100  #权重
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        10.0.0.100
    }
}

virtual_server 10.0.0.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
!    persistence_timeout 50
    protocol TCP

    real_server 10.0.0.43 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
    real_server 10.0.0.44 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
}

LVS-BACKUP

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id LVS_R2
}

vrrp_instance VI_1 {
    state BACKUP   
    interface ens33 
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        10.0.0.100
    }
}

virtual_server 10.0.0.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
!    persistence_timeout 50
    protocol TCP

    real_server 10.0.0.43 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
    real_server 10.0.0.44 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
}

2、启动lvs

service keepalived restart

备keepalived配置文件配置信息：备用服务器可以有多台，配置时候基本相同只要修改路由器名称，热备状态，优先级就可以了。
二、.节点WEB1,WEB2服务器配置
1、使用DR模式的时候，节点服务器也需要配置vip地址，并且调整内核的ARP响应参数以阻止更新VIP的MAC地址，避免发生冲突。

cd /etc/sysconfig/network-scripts/
cp ifcfg-lo  ifcfg-lo:0
vi ifcfg-lo:0

ifup lo:0
ifconfig lo:0

添加VIP本地访问路由（将访问VIP的数据限制正在本地，避免通信紊乱）

 vi /etc/rc.local

执行

route add -host 10.0.0.100 dev lo:0

2、修改内核参数。

vi /etc/sysctl.conf

（最下面添加）

echo 'net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.default.arp_ignore = 1
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2' >>/etc/sysctl.conf

注意：
arp_announce为2时：只向该网卡回应与该网段匹配的ARP报文。
arp_ignore为1：只响应目的IP地址为接收网卡上的本地地址的arp请求
其主要是实现禁止响应ARP的请求。
3、启动内核参数

sysctl  -p

4、安装httpd，创建网页测试lvs集群
WEB1

yum -y install  httpd
echo "WEB1" >/var/www/html/index.html
systemctl start httpd	

WEB2

yum -y install httpd
echo "WEB2" >/var/www/html/index.html
systemctl start httpd	

测试：

ipvsadm  -lnc

在没有vip的服务curl一下，浏览器有缓存，就算开启无痕也是一样，要命令行curl