You may find that req.connection.remoteAddress does not have the user's IP address, especially in a hosted environment. The solution is to use req.headers['x-forwarded-for'], if available. Otherwise use req.connection.remoteAddress. For example:

exports.getIPAddress = function(req) {
    return req.headers['x-forwarded-for'] || req.connection.remoteAddress;
};

There's no place like 127.0.0.1!