Finally I've found mapLimit from async library to do it. :)
async.mapLimit(dev.ips, 1, function(info, next){
var targets = new Targets(info);
targets.save(function(err, doc) {
ips.push(doc._id);
next();
});
}, function(err, results){
var netw = new Net({"net": dev.net, "ips":ips});
netw.save(function(){
console.log("guardado")
});
});
Do you know a better option?