node服务监听端口失败

处理方式之一：

# 管理员模式打开cmd运行
net stop winnat
net start winnat

报错信息：

Error: listen EACCES: permission denied 127.0.0.1:4000
    at Server.setupListenHandle [as _listen2] (net.js:1303:21)
    at listenInCluster (net.js:1368:12)
    at GetAddrInfoReqWrap.doListen [as callback] (net.js:1505:7)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:71:8)
Emitted 'error' event on Server instance at:
    at emitErrorNT (net.js:1347:8)
    at processTicksAndRejections (internal/process/task_queues.js:82:21) {
  code: 'EACCES',
  errno: -4092,
  syscall: 'listen',
  address: '127.0.0.1',
  port: 4000
}