'use strict'; const common = require('../common'); const net = require('net'); function check(addressType) { const server = net.createServer(function(client) { client.end(); server.close(); }); const address = addressType === 4 ? '127.0.0.1' : '::1'; server.listen(0, address, function() { net.connect(this.address().port, address) .on('lookup', common.mustNotCall()); }); } check(4); common.hasIPv6 && check(6);