If your network administrator has blocked (using a proxy or firewall) any outgoing ssh connection (port 22) and you can't pull, clone, push, from a remote repository you can fix it by using the https protocol.
Testing applications is a critical part of software development as illustrated by the rise of continuous integration and automated testing. In his upcoming LinuxCon + ContainerCon talk -- Testing Applications with Traffic Control in Containers -- Alban Crequy will focus on one area of testing that is difficult to automate: poor network connectivity. He will describe a testing approach which emulates network connectivity and which integrates existing Linux kernel features into higher level tools such as Kubernetes and Weave Scope.
On CentOS 7 or RHEL 7 it's important to understand the proper use of the NetworkManager daemon.
Linus Torvalds: We've had a week since the merge window closed, and rc2 is out. Go test it.
Youker Assistant is Linux system maintenance application built by Ubuntu Kylin