However, most packet-filters are stateless, understand only low-level protocols, and are difficult to configure and verify.

然而，多数包过滤是不分国家的，它们只懂得低级协议，难以配置和验证。

youdao

However, most packet-filters are stateless, understand only low-level protocols, and are difficult to configure and verify.

然而，多数包过滤是不分国家的，它们只懂得低级协议，难以配置和验证。

youdao