填空题 6.  Clientless deployments require that the user open a web browser, which acts as the VPN client, and the VPN gateway acts as a ______ device to the internal resources. 无客户端VPN的部署需要用户使用Web浏览器作为VPN客户端，而VPN网关扮演一台连接到内部资源的 ______ 设备。