当我在 Ubuntu 中执行以下命令时：
curl -v --insecure -XGET 'https://user:pass@IP_ADDR:PORT/SOME_FILE.php'
我得到这个输出：
* Hostname was NOT found in DNS cache
* Trying IP_ADDR...
* Connected to IP_ADDR (IP_ADDR) port PORT (#0)
* successfully set certificate verify locations:
* CAfile: none
CApath: /etc/ssl/certs
* SSLv3, TLS handshake, Client hello (1):
几分钟后，我得到了这个：
* Unknown SSL protocol error in connection to IP_ADDR:PORT
* Closing connection 0
curl: (35) Unknown SSL protocol error in connection to IP_ADDR:PORT
当我在 CentOS 中尝试同样的事情时，我仍然卡在Client Hello，但最后我得到了这个：
curl: (28) Operation timed …