前言：

在生产环境中，公网与内网都是独立分开的，所以称之为双网络。公网和内网在故障时实现同步漂移，例如：Keepalived+LVS-NAT 模式，这时就需要用到vrrp_sync_group设置同步漂移组。如果做双主双活，需要分别在两端加2个VIP，以达到互为主备的效果。

1.示意图：

• 多播IP是：224.0.0.111。
• 内网VIP1与内网VIP2互为主备。
• 公网VIP1与公网VIP2互为主备。
• 内网VIP1和公网VIP1是为一个同步组。
• 内网VIP2和公网VIP2是为一个同步组。

                        +------+
			|Client|
			+------+
                           /\
		       +--------+   
                       |Internet|
		       +--------+
                           /\
		       +--------+  
                       |NAT 网络|
		       +--------+
                           /\
                +----------------------+
                | 内网VIP1:10.16.8.100 |
	        | 内网VIP2:10.16.8.101 |
                +----------------------+
                   /                \
+-----------------------+      +-----------------------+
|      KA+Lvs-NAT       |      |       KA+Lvs-NAT      |
|内网VIP1:Master (eth1) |      |内网VIP1:BACKUP (eth1) |
|内网VIP2:BACKUP (eth1) |      |内网VIP2:Master (eth1) |
|内网:10.16.8.10 (eth1) |<---->|内网:10.16.8.11 (eth1) |
|-----------------------|多播IP|-----------------------|
|公网VIP1:Master (eth2) |<---->|公网VIP1:BACKUP (eth2) |
|公网VIP2:BACKUP (eth2) |      |公网VIP2:Master (eth2) |
|公网:172.16.8.10(eth2) |      |公网:172.16.8.11(eth2) |                 
+-----------------------+      +-----------------------+
                   \                /
		+-----------------------+	 
                | 公网VIP1:172.16.8.100 |
		| 公网VIP2:172.16.8.101 |
		+-----------------------+
		           \/
			+------+
			|资源池|
		        +------+

2.ka67配置文件

global_defs {
   notification_email {
     root@localhost
   }
   notification_email_from ka@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id ka67
   vrrp_mcast_group4 224.0.0.111
}
vrrp_sync_group VG_1 {
    group {
        External_1
        Internal_1
    }
}
vrrp_sync_group VG_2 {
    group {
        External_2
        Internal_2
    }
}
vrrp_instance External_1 {
    state MASTER
    interface eth1
    virtual_router_id 171
    priority 100
    advert_int 1    
    authentication {
        auth_type PASS
        auth_pass renwole0
    }
    virtual_ipaddress {
        10.16.8.100
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}
vrrp_instance External_2 {
    state BACKUP
    interface eth1
    virtual_router_id 172
    priority 95
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass renwole1
    }
    virtual_ipaddress {
        10.16.8.101
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}
vrrp_instance Internal_1 {
    state MASTER
    interface eth2
    virtual_router_id 191
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass renwole2
    }
    virtual_ipaddress {
        172.16.8.100
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}
vrrp_instance Internal_2 {
    state BACKUP
    interface eth2
    virtual_router_id 192
    priority 95
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass renwole3
    }
    virtual_ipaddress {
        172.16.8.101
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}

3.ka68配置文件

global_defs {
   notification_email {
     root@localhost
   }
   notification_email_from ka@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id ka68
   vrrp_mcast_group4 224.0.0.111
}
vrrp_sync_group VG_1 {
    group {
        External_1
        Internal_1
    }
}
vrrp_sync_group VG_2 {
    group {
        External_2
        Internal_2
    }
}
vrrp_instance External_1 {
    state BACKUP
    interface eth1
    virtual_router_id 171
    priority 100
    advert_int 1    
    authentication {
        auth_type PASS
        auth_pass renwole0
    }
    virtual_ipaddress {
        10.16.8.100
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}
vrrp_instance External_2 {
    state MASTER
    interface eth1
    virtual_router_id 172
    priority 95
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass renwole1
    }
    virtual_ipaddress {
        10.16.8.101
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}
vrrp_instance Internal_1 {
    state BACKUP
    interface eth2
    virtual_router_id 191
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass renwole2
    }
    virtual_ipaddress {
        172.16.8.100
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}
vrrp_instance Internal_2 {
    state MASTER
    interface eth2
    virtual_router_id 192
    priority 95
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass renwole3
    }
    virtual_ipaddress {
        172.16.8.101
    }
    notify_master "/usr/local/keepalived/etc/keepalived/notify.sh master"
    notify_backup "/usr/local/keepalived/etc/keepalived/notify.sh backup"
    notify_fault "/usr/local/keepalived/etc/keepalived/notify.sh fault"
}