Local unit test errors, but the remote one is OK with me

[ghost]

I've been running with the problem for a couple of months when contributing to Egg project—— I ALWAYS see errors in the next three cases：

After a detail discussion with @fengmk2，I changed my DNS setting to this following：

Then the dns unit tests' erros above are GONE~~~
But another new question comes to me：

So I just wonder how we make this the same as what we see in the remote server of Egg, you see that when submitting to the remote server to check CI, everything is right.