54 lines
1.2 KiB
Markdown
54 lines
1.2 KiB
Markdown
# Telnet 测试端口连通性
|
||
|
||
telnet命令是TELNET协议的用户接口，它支持两种模式：命令模式和会话模式，虽然telnet支持许多命令，但大部分情况下，我们只是使用它查看目标主机是否打开了某端口（默认是23）。
|
||
|
||
其执行结果有两种：
|
||
|
||
## 端口未打开
|
||
|
||
```bash
|
||
telnet 101.199.97.65 62715
|
||
Trying 101.199.97.65...
|
||
telnet: connect to address 101.199.97.65: Connection refused
|
||
```
|
||
|
||
此时，命令已退出。
|
||
|
||
## 端口已打开
|
||
|
||
```bash
|
||
telnet 101.199.97.65 62715
|
||
Trying 101.199.97.65...
|
||
Connected to 101.199.97.65.
|
||
Escape character is '^]'.
|
||
```
|
||
|
||
此时命令未退出。
|
||
|
||
根据提示Escape character is '^]'.可知退出字符为'^]'（CTRL+]）。此时输入其它字符不能使其退出，CTRL+C都不行。输入CTRL+]后会自动执行，进入命令模式：
|
||
|
||
```bash
|
||
^]
|
||
telnet>
|
||
```
|
||
|
||
此时再运行 quit 才会真正退出。
|
||
|
||
```bash
|
||
telnet> quit
|
||
Connection closed.
|
||
```
|
||
|
||
其中，Escape character 可以自定义，使用参数 -e：
|
||
|
||
```bash
|
||
telnet -e p 101.199.97.65 62715 #使用p字符
|
||
Telnet escape character is 'p'.
|
||
Trying 101.199.97.65...
|
||
Connected to 101.199.97.65.
|
||
Escape character is 'p'.
|
||
p
|
||
telnet> quit
|
||
Connection closed.
|
||
```
|