Please provide the types of information described in "How to report an issue".
You are trying to persuade contributors to an open source project to give their time to answer your question. Without sufficient information, they are much less likely to help you.
In this particular case, you'll probably need to provide information about your network configuration, including things like the country where you are located (are you behind the great firewall in China), proxy configuration (is there an http proxy between you and the internet), Jenkins log files (do the log files provide any hints), and more.
Please provide the types of information described in "How to report an issue".
You are trying to persuade contributors to an open source project to give their time to answer your question. Without sufficient information, they are much less likely to help you.
In this particular case, you'll probably need to provide information about your network configuration, including things like the country where you are located (are you behind the great firewall in China), proxy configuration (is there an http proxy between you and the internet), Jenkins log files (do the log files provide any hints), and more.