Which operating system?
Linux has `getifaddrs
<http://man7.org/linux/man-pages/man3/getifaddrs.3.html>`_, but it doesn't seem
to be wrapped in `posix <http://nim-lang.org/docs/posix.html>`_, so you have to
wrap it yourself.
Windows has `GetAdaptersAddresses
<https://msdn.microsoft.com/en-us/library/windows/desktop/aa365915(v=vs.85).aspx>`_,
which you also have to wrap yourself since it isn't part of `winlean
<http://nim-lang.org/docs/winlean.html>`_.
There may be packages which I don't know of that make this easier.
