路由器子接口接入

参考文献：

https://www.zabbx.cn/archives/%E5%8D%8E%E4%B8%BA%E4%BA%8C%E5%B1%82%E4%BA%A4%E6%8D%A2%E6%9C%BA%E5%AF%B9%E6%8E%A5%E8%B7%AF%E7%94%B1%E5%99%A8%E2%80%94%E5%8D%95%E8%87%82%E8%B7%AF%E7%94%B1%EF%BC%88%E5%AD%90%E6%8E%A5%E5%8F%A3%EF%BC%89