懸空 CNAME 記錄問題

我一直在嘗試使用 Amazon SES 為我的一個子域設置 DKIM CNAME 簽名，但由於某種原因，CNAME 的行為很奇怪：

例如。

以下：

dig @4.2.2.4 pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com

有時返回：

; <<>> DiG 9.8.3-P1 <<>> @4.2.2.4 pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10537
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. IN A

;; ANSWER SECTION:
pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. 170 IN CNAME support.formsdotstar.com.
support.formsdotstar.com. 170   IN  A   23.239.84.67

;; Query time: 223 msec
;; SERVER: 4.2.2.4#53(4.2.2.4)
;; WHEN: Wed May 11 22:56:02 2016
;; MSG SIZE  rcvd: 116

在其他時候返回：

; <<>> DiG 9.8.3-P1 <<>> @4.2.2.4 pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31484
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. IN A

;; ANSWER SECTION:
pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. 174 IN CNAME pznfjjljalcr5ocdaxrjia27nbf7cial.dkim.amazonses.com.

;; AUTHORITY SECTION:
dkim.amazonses.com. 774 IN  SOA ns-386.awsdns-48.com. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400

;; Query time: 232 msec
;; SERVER: 4.2.2.4#53(4.2.2.4)
;; WHEN: Wed May 11 22:56:01 2016
;; MSG SIZE  rcvd: 226

最初我認為這是一個傳播問題，但它出現在同一個 DNS 伺服器上。

有什麼問題？

您的 formsdotstar.com 的四個名稱伺服器正在返回不同的答案：

$ dig @ns1bqx.name.com pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com
;; ANSWER SECTION:
pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. 300 IN CNAME pznfjjljalcr5ocdaxrjia27nbf7cial.dkim.amazonses.com.

dig @ns2dfg.name.com pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com
;; ANSWER SECTION:
pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. 300 IN CNAME support.formsdotstar.com.
support.formsdotstar.com. 300   IN  A   23.239.84.67

$ dig @ns3dkz.name.com pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com
;; ANSWER SECTION:
pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. 300 IN CNAME pznfjjljalcr5ocdaxrjia27nbf7cial.dkim.amazonses.com.

$ dig @ns4ghm.name.com pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com
;; ANSWER SECTION:
pznfjjljalcr5ocdaxrjia27nbf7cial._domainkey.support.formsdotstar.com. 300 IN CNAME support.formsdotstar.com.
support.formsdotstar.com. 300   IN  A   23.239.84.67

引用自：https://serverfault.com/questions/776189