是我的网络被其他人使用 [英] is my network being used by someone else

问题描述

Linux中nmap的输出如下：

启动Nmap 5.21（http://nmap.org）于2013-12-13 21:25 IST

local.gateway的Nmap扫描报告（192.168.1.1）

主机启动（延迟0.0011秒）。

MAC地址：00：0F：A3：75：27 ：5A（Alpha Networks）

Nmap扫描报告为192.168.1.2

主机已启动。

完成Nmap：256个IP地址（2个主机） up）18.48秒扫描



笔记本电脑连接到我的调制解调器。但是它显示了两个主机？

The output of nmap in Linux is as follows:
Starting Nmap 5.21 ( http://nmap.org ) at 2013-12-13 21:25 IST
Nmap scan report for local.gateway (192.168.1.1)
Host is up (0.0011s latency).
MAC Address: 00:0F:A3:75:27:5A (Alpha Networks)
Nmap scan report for 192.168.1.2
Host is up.
Nmap done: 256 IP addresses (2 hosts up) scanned in 18.48 seconds

I have laptop connected to my modem. but it shows two hosts?

推荐答案

调制解调器得到一个IP，你得到一个。所以2个主持人。

The modem gets an IP, and you get one. So 2 hosts.

Ron Beyer给了你一个正确答案。只是一个解释：

你可能有一个电缆或DSL调制解调器。这些是网关（如主机名称所示）和网桥 - 可能与其他功能集成，如交换，路由，防火墙，NAT等。

作为一个调制解调器，它也是一个桥梁，它连接在网络的第2层（数据链路）和第1层（物理）以及在不同物理介质上运行的提供商网络。但是你没有看到这一点。

网关是一种服务（在设备上），位于网络的第3层（网络层），允许您与网络外的世界进行通信。如果您的主机无法直接与其他主机通信，因为它不在您的网络上，它会将数据包发送到网关。由于它在L3中，因此必须在您的网络上拥有一个地址。使用IPv4时，它具有IPv4地址。您可以在界面上检查该地址是否设置为默认网关：只需输入 ifconfig [ ^ ]。



查看更多：

http://www.sis.pitt.edu/ ~icucart / networking_basics / 4LayersofTCPIPModel.html [ ^ ]

https://supportforums.cisco.com/docs/DOC -17626 [ ^ ]

Ron Beyer gave you a correct answer. Just an explanation:
You probably have a cable or DSL "modem". Those are gateways (as you see in the host's name) and bridges - probably integrated with other functionality like switching, routing, firewall, NAT, and so on.
As a modem it is a bridge too, which is linking on Layer 2 (data link) and Layer 1 (physical) your network and the network of your provider which are running on different physical media. But you don't see this.
A gateway is a service (on a device) sitting on Layer 3 (network layer) in your network and allowing you to communicate with the world outside your network. If your host can not directly communicate with an other host, because it is not on your network, it will send the packets to the gateway. As it is in L3 it has to have an address on your network. As you use IPv4, it has an IPv4 address. You can check that address being set as default gateway on your interface: just type ifconfig[^].

See more:
http://www.sis.pitt.edu/~icucart/networking_basics/4LayersofTCPIPModel.html[^]
https://supportforums.cisco.com/docs/DOC-17626[^]

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