公众号的微网站开发,桂林北站附近酒店,昆山市建设监察大队官方网站,特效型网站1.命令简介
nc#xff08;netcat#xff09;是一个短小精悍、功能实用、简单可靠的网络工具#xff0c;主要有如下作用#xff1a;
#xff08;1#xff09;端口侦听#xff0c;nc 可以作为 server 以 TCP 或 UDP 方式侦听指定端口#xff1b;
#xff08;2#x…1.命令简介
ncnetcat是一个短小精悍、功能实用、简单可靠的网络工具主要有如下作用
1端口侦听nc 可以作为 server 以 TCP 或 UDP 方式侦听指定端口
2端口扫描nc 可以作为 client 发起 TCP 或 UDP 请求
3机器之间传输文件
4机器之间网络测速。
2.命令格式
nc [-46DdhklnrStUuvzC] [-i interval] [-p source_port] [-s source_ip_address] [-T ToS] [-w timeout] [-X proxy_protocol] [-x proxy_address[:port]] [hostname] [port[s]]常用选项
-4只使用 IPv4 地址-6只使用 IPv6 地址-l启动本地监听-n不使用 DNS 解析-p指定源端口-s指定源 IP 地址-u使用 UDP默认是 TCP-v显示详细信息-w设定超时时间只适合用在 Client 端-d禁止从标准输入读取数据也就是客户端输入数据不会发送到服务端-k让服务端保持连接不断开
3.常用示例
模拟服务端
nc -vkl 8080模拟客户端
nc -v 127.0.0.1 8888连接日志
#server
rootVM-16-3-ubuntu:~# nc -vkl 8080
Listening on 0.0.0.0 8080
Connection received on localhost 42930#client
rootVM-16-3-ubuntu:~# nc -v 127.0.0.1 8080
Connection to 127.0.0.1 8080 port [tcp/http-alt] succeeded!
#随后双方便可输入消息发送发送文件
nc 不仅可以发送消息还可发送文件。
假设服务端有一个 out.txt 的空文件而客户端有一个 in.txt 文件含有数据hello server。
Server 端接收文件
nc localhost 6000 out.txtClient 端发送文件
nc localhost 6000 in.txt之后我们可以看到 Server 端的 out.txt 文件中已经有数据了
# cat out.txt
hello server除了可以发送文件nc 也可以发送目录只需要将目录压缩发送即可。
端口扫码
端口扫描是一个非常重要的功能很多时候系统管理员会通过扫描服务器上端口来识别系统中漏洞nc 工具提供了非常方便的操作
nc -vz 127.0.0.1 1-100这条命令扫描 192.168.1.3 上 1-100 端口区间有哪些端口是开放的。
# nc -vz 127.0.0.1 1-100
nc: connect to 127.0.0.1 port 1 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 2 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 3 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 4 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 5 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 6 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 7 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 8 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 9 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 10 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 11 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 12 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 13 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 14 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 15 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 16 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 17 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 18 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 19 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 20 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 21 (tcp) failed: Connection refused
Connection to 127.0.0.1 22 port [tcp/ssh] succeeded!
nc: connect to 127.0.0.1 port 23 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 24 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 25 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 26 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 27 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 28 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 29 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 30 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 31 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 32 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 33 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 34 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 35 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 36 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 37 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 38 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 39 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 40 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 41 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 42 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 43 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 44 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 45 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 46 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 47 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 48 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 49 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 50 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 51 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 52 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 53 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 54 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 55 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 56 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 57 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 58 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 59 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 60 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 61 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 62 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 63 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 64 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 65 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 66 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 67 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 68 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 69 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 70 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 71 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 72 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 73 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 74 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 75 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 76 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 77 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 78 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 79 (tcp) failed: Connection refused
Connection to 127.0.0.1 80 port [tcp/http] succeeded!
nc: connect to 127.0.0.1 port 81 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 82 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 83 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 84 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 85 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 86 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 87 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 88 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 89 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 90 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 91 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 92 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 93 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 94 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 95 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 96 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 97 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 98 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 99 (tcp) failed: Connection refused
nc: connect to 127.0.0.1 port 100 (tcp) failed: Connection refused可以看到只有 22和80号端口是开放的。
总结
nc 通过在两台机器之间建立连接来完成很多网络功能数据传输、网络连接、端口扫描等也有助于我们进行网络调试排查网络故障。
