为什么 dig 解析 ipv6 拿不到 AAAA 地址

[DinoStray]

用 dig 试了 百度 和 google 的 ipv6 DNS 解析, 结果类似, 都是有一个 CNAME , 一个 SOA, 没有 AAAA 的结果, 为啥拿不到 ipv6 的地址呢

dig AAAA ipv6.google.com

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> AAAA ipv6.google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5549
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;ipv6.google.com.               IN      AAAA

;; ANSWER SECTION:
ipv6.google.com.        268628  IN      CNAME   ipv6.l.google.com.

;; AUTHORITY SECTION:
l.google.com.           6       IN      SOA     ns1.google.com. dns-admin.google.com. 314006931 900 900 1800 60

;; Query time: 0 msec
;; SERVER: 100.100.2.136#53(100.100.2.136)
;; WHEN: Mon Jun 01 07:45:43 UTC 2020
;; MSG SIZE  rcvd: 104

[DinoStray]

很奇怪, 在我的测试机不行, 换生产环境就 OK 了, 搞不懂为什么

```
# dig AAAA www.google.com

; <<>> DiG 9.10.3-P4-Ubuntu <<>> AAAA www.google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40761
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.google.com. IN AAAA

;; ANSWER SECTION:
www.google.com. 53 IN AAAA 2001::c73b:9588

;; Query time: 0 msec
;; SERVER: 100.100.2.136#53(100.100.2.136)
;; WHEN: Mon Jun 01 16:03:01 CST 2020
;; MSG SIZE rcvd: 60

```