While main NS-3 repository [1] uses Mercurial, NS-3 also has official [2] git mirror [3]. Added .gitignore replicates current .hgignore, also taking advantage of the ability to split it into multiple files. [1] http://code.nsnam.org/ns-3-dev/ [2] https://www.nsnam.org/wiki/HOWTO_use_Git_instead_of_Mercurial [3] https://github.com/nsnam/ns-3-dev-git