套接字gethostbyname未显示nslookup命令响应

Question

example.com 的子域只能从我的网络的Intranet进行查询（nslookup仅在该网络内响应）。问题是我在网络内部，并且nslookup可以正确响应，但是socket.gethostbyname引发了异常。

nslookup 命令返回：

Server:     172.16.11.200
Address:    172.16.11.200#53

Non-authoritative answer:
example.example.com canonical name = example-elb-174457708.eu-west-1.elb.amazonaws.com.

socket.gethostbyname 返回：

python -c "import socket; print(socket.gethostbyname_ex('example.example.com'))"


Traceback (most recent call last):
  File "<string>", line 1, in <module>
socket.gaierror: [Errno -2] Name or service not known