GitHub - HTTPS access

I am unable to clone my repository via HTTPS:

$ git clone https://github.com/walterjwhite/project.configuration.git
Initialized empty Git repository in ./project.configuration/.git/
error: Failed connect to github.com:443; Connection refused while accessing https://github.com/walterjwhite/project.configuration.git/info/refs
fatal: HTTP request failed

I have configured .netrc with my login and password as well as the machine or server I am connecting to.

As you did saw yourself in GitHub support, Scott Schacon himself suggested:

So I guess your .netrc is incorrect or something?
Try removing the info from your .netrc and cloning first (since it's a public repo).

If it isn't a GitHub server issue, it could be your firewall.
And/or your proxy (git config --global http.proxy http://user:password@proxy:xxx).

Just to add to this discussion, for some reason or another, it seems to work for me when I use http rather than https.