求翻译：本文讲述的是网络当中局域网的安全及维护，主要是从局域网结构特点、局域网安全分类、局域网安全防范措施等方面内容是什么意思？

This article describes the safety and maintenance of LAN network which, from the aspects of the structural features of the LAN, LAN security classification, LAN security precautions

This article is about the network of local area network security and maintenance, is mainly from the local area network, structural features, Domain Internet security classification, the local area network security measures, and so

This article narrates is in the middle of the network the local area network security and the maintenance, mainly is from local area network aspect contents and so on unique feature, local area network safe classification, local area network safe guard measure

This article about the network security and maintenance of local area networks, classification of main structural features, and is from a local area network LAN security, LAN security measures and other aspects

正在翻译，请等待...