我注意到AWS的DNS服务(Route53)在每个DNS网址的末尾附加一个点(.)：
ns-xxx.awsdns-yy.co.uk. ns-xxx.awsdns-yy.net. ns-xxx.awsdns-yy.org. ns-xxx.awsdns-yy.com.
解决方法
最后的点是正确的.
这是一个鲜为人知的事实,但完全合格(明确的)DNS域名最后有一个点.运行DNS服务器的人通常都知道这一点(如果你错过了尾随点,你的DNS配置不太可能有效),但一般公众通常不会这样做.最后没有点的域名不是完全限定的,并且可能不明确.早在1987年,DNS规范RFC 1034就记录了这一点：
Since a complete domain name ends with the root label,this leads to a
printed form which ends in a dot. We use this property to distinguish between:
- a character string which represents a complete domain name
(often called "absolute"). For example,"poneria.ISI.EDU."
- a character string that represents the starting labels of a
domain name which is incomplete,and should be completed by
local software using knowledge of the local domain (often
called "relative"). For example,"poneria" used in the
ISI.EDU domain.
从here起