DNS error

https://stackoverflow.com/questions/9393409/ssh-could-not-resolve-hostname-github-com-name-or-service-not-known-fatal-th

ssh: Could not resolve hostname github.com: Name or service not known
fatal: The remote end hung up unexpectedly

ubuntu上：

• ping github.com, if ping failed. it is DNS error.
• sudo vim /etc/resolv.conf, then add: nameserver 8.8.8.8 nameserver 8.8.4.4
  Or it can be a genuine network issue. Restart your network-manager using sudo service network-manager restart or fix it up