Can't install ionic thru npm

I am having issues installing ionic using npm install -g ionic. I got this error:

What I have tried so far:

  1. Turn off firewall
npm set strict-ssl=false
npm config set registry "http://registry.npmjs.org/"
npm config set proxy  http://localhost:8080/ 
npm config set https-proxy  http://localhost:8080/

Still getting erorr while trying to do options above. Please help.

This seems to be a connection problem with npm and your proxy, not really Ionic. You will probably have more luck asking on StackOverflow or https://npm.community