换用acme之后，出现频繁的NXDOMAIN

直接添加单一的不带 www 的域名是没有问题的，一加 www 马上根就 NX...泛域名后面试了没有问题
What Are You Doing? 
1. Use HTTP Only 
2. Use your own SSL Certificate and Key 
3. Use Let's Encrypt to Create SSL Certificate and Key 
q. Exit 
Please input the correct option: 3 

Please input domain(example: http://www.example.com): aaa.com 
domain=aaa.com 

Please input the directory for the domain:aaa.com : 
(Default directory: /data/wwwroot/aaa.com): 
Virtual Host Directory=/data/wwwroot/aaa.com 

Create Virtul Host directory...... 
set permissions of Virtual Host directory...... 

Do you want to add more domain name? [y/n]: y 

Type domainname or IP(example: example.com other.example.com): http://www.aaa.com 
domain list=www.aaa.com 

Let's Encrypt Verify error! DNS problem: NXDOMAIN looking up A for aaa.com 

# dig aaa.com 

; <<>> DiG 9.9.4-RedHat-9.9.4-51.el7_4.2 <<>> aaa.com 
;; global options: +cmd 
;; Got answer: 
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63822 
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 

;; OPT PSEUDOSECTION: 
; EDNS: version: 0, flags:; udp: 512 
;; QUESTION SECTION: 
;aaa.com. IN A 

;; ANSWER SECTION: 
aaa.com. 599 IN A 192.74.251.xx 

;; Query time: 285 msec 
;; SERVER: 8.8.8.8#53(8.8.8.8) 
;; WHEN: Mon Mar 26 11:38:26 CST 2018 
;; MSG SIZE rcvd: 53 

# dig http://www.aaa.com 

; <<>> DiG 9.9.4-RedHat-9.9.4-51.el7_4.2 <<>> http://www.aaa.com 
;; global options: +cmd 
;; Got answer: 
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27594 
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 

;; OPT PSEUDOSECTION: 
; EDNS: version: 0, flags:; udp: 512 
;; QUESTION SECTION: 
;www.aaa.com. IN A 

;; ANSWER SECTION: 
http://www.aaa.com. 599 IN A 192.74.251.xx 

;; Query time: 309 msec 
;; SERVER: 8.8.8.8#53(8.8.8.8) 
;; WHEN: Mon Mar 26 11:38:45 CST 2018 
;; MSG SIZE rcvd: 57