Linux命令之nc命令

快来打我* 2023-10-13 13:27 12阅读 0赞

## 一、命令简介 ##

nc是netcat的简写，是一个功能强大的网络工具，有着网络界的瑞士军刀美誉。nc命令在linux系统中实际命令是ncat，nc是[软连接][Link 1]到ncat。nc命令的主要作用如下：

*  实现任意TCP/UDP端口的侦听，nc可以作为server以TCP或UDP方式侦听指定端口
 *  端口的扫描，nc可以作为client发起TCP或UDP连接
 *  机器之间传输文件
 *  机器之间网络测速  
    nc如果找不到nc命令可以使用yum install -y nc安装。
 *  ## 二、使用示例 ##
    
    1、验证服务器端口是否通  
    如下验证172.16.7.78服务器的80端口通，81端口不通。  
    ![在这里插入图片描述][6ffceecf4cf64274a96703e5c21f9af3.png_pic_center]
    
    2、拷贝文件  
    首先在文件接收终端test2机器上激活nc[监听][Link 2]  
    ![在这里插入图片描述][6b25177fc8474b5f858070a2c5552daa.png_pic_center]
    
    然后在文件发送终端test1机器上发送文件  
    ![在这里插入图片描述][562158e281f24f93b467fbd70768cfe3.png_pic_center]  
    在test2上检查文件是否已成功接收
    
    ![在这里插入图片描述][3228a5d935b940e7b81d4f1e1f829b95.png_pic_center]
    
    ## 3、终端之间通信聊天 ##
    
    test1主机上启动nc监听，ctrl+C[中断][Link 3]通信。
    
    ![在这里插入图片描述][bb7d38fe8a1d4f07b08c7d14bd20568e.png_pic_center]
    
    test2上连接监听，ctrl+C中断通信。  
    ![在这里插入图片描述][2d0c56159d634229814ea11bed3edd5d.png_pic_center]
    
    ## 4、端口扫描 ##
    
    端口扫描，通的端口返回succeeded，不通的端口返回refused。此扫描基于nc-1.84-24.el6.x86\_64。

[root@test1 /]# nc -v -w 1 172.16.7.78 -z 22-81
    Connection to 172.16.7.78 22 port [tcp/ssh] succeeded!
    nc: connect to 172.16.7.78 port 23 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 24 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 25 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 26 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 27 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 28 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 29 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 30 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 31 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 32 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 33 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 34 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 35 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 36 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 37 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 38 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 39 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 40 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 41 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 42 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 43 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 44 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 45 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 46 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 47 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 48 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 49 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 50 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 51 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 52 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 53 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 54 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 55 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 56 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 57 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 58 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 59 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 60 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 61 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 62 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 63 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 64 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 65 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 66 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 67 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 68 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 69 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 70 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 71 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 72 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 73 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 74 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 75 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 76 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 77 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 78 (tcp) failed: Connection refused
    nc: connect to 172.16.7.78 port 79 (tcp) failed: Connection refused
    Connection to 172.16.7.78 80 port [tcp/http] succeeded!
    nc: connect to 172.16.7.78 port 81 (tcp) failed: Connection refused

## 5、验证[UDP][]端口 ##

[root@test1 ~]# nc -uvz 192.168.0.125 111
    Ncat: Version 7.50 ( https://nmap.org/ncat )
    Ncat: Connected to 192.168.0.125:111.
    Ncat: UDP packet sent successfully
    Ncat: 1 bytes sent, 0 bytes received in 2.04 seconds.

参考 ：[linux nc命令参数及用法详解--功能超级强大的网络工具netcat - Linux安全网 - Linux操作系统\_Linux 命令\_Linux教程\_Linux黑客][linux nc_--_netcat - Linux_ - Linux_Linux _Linux_Linux]

NC工具的使用说明教程：[NC工具的使用说明教程\_nc: cannot use -p and -l\_Xysoul的博客-CSDN博客][NC_nc_ cannot use -p and -l_Xysoul_-CSDN]

window 版本 nc 下载：[netcat 1.11 for Win32/Win64][netcat 1.11 for Win32_Win64]

来自 [Linux命令之nc命令\_Mr-Wanter的博客-CSDN博客][Linux_nc_Mr-Wanter_-CSDN]

[Link 1]: https://so.csdn.net/so/search?q=%E8%BD%AF%E8%BF%9E%E6%8E%A5&spm=1001.2101.3001.7020
[6ffceecf4cf64274a96703e5c21f9af3.png_pic_center]: https://img-blog.csdnimg.cn/6ffceecf4cf64274a96703e5c21f9af3.png#pic_center
[Link 2]: https://so.csdn.net/so/search?q=%E7%9B%91%E5%90%AC&spm=1001.2101.3001.7020
[6b25177fc8474b5f858070a2c5552daa.png_pic_center]: https://img-blog.csdnimg.cn/6b25177fc8474b5f858070a2c5552daa.png#pic_center
[562158e281f24f93b467fbd70768cfe3.png_pic_center]: https://img-blog.csdnimg.cn/562158e281f24f93b467fbd70768cfe3.png#pic_center
[3228a5d935b940e7b81d4f1e1f829b95.png_pic_center]: https://img-blog.csdnimg.cn/3228a5d935b940e7b81d4f1e1f829b95.png#pic_center
[Link 3]: https://so.csdn.net/so/search?q=%E4%B8%AD%E6%96%AD&spm=1001.2101.3001.7020
[bb7d38fe8a1d4f07b08c7d14bd20568e.png_pic_center]: https://img-blog.csdnimg.cn/bb7d38fe8a1d4f07b08c7d14bd20568e.png#pic_center
[2d0c56159d634229814ea11bed3edd5d.png_pic_center]: https://img-blog.csdnimg.cn/2d0c56159d634229814ea11bed3edd5d.png#pic_center
[UDP]: https://so.csdn.net/so/search?q=UDP&spm=1001.2101.3001.7020
[linux nc_--_netcat - Linux_ - Linux_Linux _Linux_Linux]: http://www.linuxso.com/command/nc.html
[NC_nc_ cannot use -p and -l_Xysoul_-CSDN]: https://blog.csdn.net/xysoul/article/details/52270149
[netcat 1.11 for Win32_Win64]: https://eternallybored.org/misc/netcat/
[Linux_nc_Mr-Wanter_-CSDN]: https://blog.csdn.net/mr_wanter/article/details/125076995