TCP/IP 中的常用术语和概念如下所述/Common terms and concepts in TCP/IP are defined as follows:
　　1. 节点 任何运行一个 IP 实现的设备（包括路由器和主机）
　　• Node Any device, including routers and hosts, which runs an implementation of IP.
　　
　　2. 路由器 可转发未显式定址到其自身的 IP 数据包的节点。在 IPv6 网络上，路由器通常还公布其存在和主机配置信息。
　　• Router A node that can forward IP packets not explicitly addressed to itself. On an IPv6 network, a router also typically advertises its presence and host configuration information.
　　
　　3. 主机 无法转发未显式定址到其自身的 IP 数据包的节点（非路由器）。通常，主机是 IP 通信量的源和目标。主机会悄悄地丢弃它接收到的、未显式定址到其自身的通信量。
　　• Host A node that cannot forward IP packets not explicitly addressed to itself (a non-router). A host is typically the source and the destination of IP traffic. A host silently discards traffic that it receives but that is not explicitly addressed to itself.
　　
　　4. 上层协议位 于IP 之上并将 IP 用作其传输层的协议。示例包括 Internet 层协议（如 Internet 控制消息协议 (ICMP)）和传输层协议（如传输控制协议 (TCP) 和用户数据报协议 (UDP)）。（但是，将 TCP 和 UDP 用作传输层的应用层协议不属于上层协议。文件传输协议 [FTP] 和域名系统 [DNS] 属于这类应用层协议）。有关 TCP/IP 协议套件各层的详细信息，请参见第 2 章“TCP/IP 协议套件体系结构概述”。
　　• Upper-layer protocol A protocol above IP that uses IP as its transport. Examples include Internet layer protocols such as the Internet Control Message Protocol (ICMP) and Transport layer protocols such as the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). (However, Application layer protocols that use TCP and UDP as their transports are not considered upper-layer protocols. File Transfer Protocol [FTP] and Domain Name System [DNS] fall into this category). For details of the layers of the TCP/IP protocol suite, see Chapter 2, "Architectural Overview of the TCP/IP Protocol Suite [ http://technet.microsoft.com/en-us/library/bb726993.aspx ] ."
　　
　　5. 局域网网段 子网的一部分，由受桥或第 2 层交换机约束的单个媒体构成。
　　• LAN segment A portion of a subnet consisting of a single medium that is bounded by bridges or Layer 2 switches.
　　
　　6. 子网 一个或多个受路由器约束的、使用同一 IP 地址前缀的局域网网段。子网有时还被称为网段和链路。
　　• Subnet One or more LAN segments that are bounded by routers and use the same IP address prefix. Other terms for subnet are network segment and link.
　　
　　7. 网络 两个或多个通过路由器连接的子网。网络有时还被称为互联网络 (internet work)。
　　• Network Two or more subnets connected by routers. Another term for network is internetwork.
　　
　　8. 邻居 连接到同一子网的不同节点互为邻居。
　　• Neighbor A node connected to the same subnet as another node.
　　
　　9. 接口 节点与子网的物理或逻辑连接的表示形式。物理接口的一个示例是网络适配器。逻辑接口的一个示例是用于通过 IPv4 网络发送 IPv6 数据包的隧道接口。
　　• Interface The representation of a physical or logical attachment of a node to a subnet. An example of a physical interface is a network adapter. An example of a logical interface is a tunnel interface that is used to send IPv6 packets across an IPv4 network.
　　
　　10. 地址 在 Internet 层分配给一个接口或一组接口的、可用作 IP 数据包的源或目标的标识符。
　　• Address An identifier that can be used as the source or destination of IP packets and that is assigned at the Internet layer to an interface or set of interfaces.
　　
　　11. 数据包 存在于 Internet 层的、由 IP 标头和有效负载构成的协议数据单元 (PDU)。
　　• Packet The protocol data unit (PDU)协议数据单元 that exists at the Internet layer and comprises an IP header and payload IP标头和有效负载.[biggrin][biggrin]文字