linux系统下nc工具查看tcp/udp端口服务

#### 前言

linux系统环境下，可通过nc工具既可查看tcp端口服务，亦可查看udp端口服务

 

#### 安装nc工具

> yum -y install nc

 

#### 测试端口服务

 

##### 测试tcp端口服务

语法:

> nc -z -v [hostname/IP address] [port number]

 

tcp端口服务存在示例:

> nc -zv 192.168.110.7 3306

```

Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.110.7:3306.
Ncat: 0 bytes sent, 0 bytes received in 0.02 seconds.

```

 

tcp端口服务不存在示例:

> nc -zv 192.168.110.7 3307   

```

Ncat: Connection refused

```

 

##### 测试udp端口服务

语法:

> nc -z -v -u [hostname/IP address] [port number]

 

tcp端口服务存在示例:

> nc -zvu 192.168.110.7 3306

```

Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.110.7:3306.
Ncat: UDP packet sent successfully
Ncat: 1 bytes sent, 0 bytes received in 2.02 seconds.

```

 

tcp端口服务不存在示例:

> nc -zv 192.168.110.7 3307   

```

Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.110.7:3306.
Ncat: Connection refused

```