keepalived 配置的 EQUAL 状态是什么意思？

我面临着新的，“状态”变量的未知值 - “EQUAL”。更加详细一些：

vrrp_script chk_master {
    script "/var/<path>/scripts/cmaster.sh"
    timeout 25
    interval 30
    weight -120
}

vrrp_instance VI {
        interface eth0
        state EQUAL
        priority 101
        virtual_router_id 68
        advert_int 1
        authentication {
                auth_type PASS
                auth_pass password:
        }
        virtual_ipaddress {
                x.x.x.x/x
        }

        track_script {
            chk_master
        }

        notify /usr/local/bin/keepalived-notify.sh
}

vrrp_script chk_standby {
    script "/var/<path>/scripts/cstandby.sh"
    timeout 25
    interval 30
    weight 20
}

vrrp_instance VI2 {
        interface eth0
        state EQUAL
        priority 100
        virtual_router_id 69
        advert_int 1
        authentication {
                auth_type PASS
                auth_pass password:
        }
        virtual_ipaddress {
                x.x.x.x/x
        }

        track_script {
            chk_standby
        }

        notify /usr/local/bin/keepalived-notify2.sh
}

有人知道这种状态是什么意思吗？“EQUAL”和“MASTER”/“BACKUP”状态有什么区别？我在官方文档中没有找到答案。谢谢。