判断端口通不通的几种方法

最新推荐文章于 2025-06-12 19:27:05 发布

转载最新推荐文章于 2025-06-12 19:27:05 发布 · 1.8w 阅读

linux 专栏收录该内容

33 篇文章

订阅专栏

本文介绍了三种常见的端口检测方法：使用telnet、ssh和wget工具。通过这些工具，可以判断目标主机上的端口是否开放。文章详细展示了每种工具的具体用法及如何解读其输出结果。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1、使用telnet判断
telnet是windows标准服务，可以直接用；如果是linux机器，需要安装telnet.
用法: telnet ip port
1）先用telnet连接不存在的端口
[root@localhost ~]# telnet 10.0.250.3 80
Trying 10.0.250.3...
telnet: connect to address 10.0.250.3: Connection refused #直接提示连接被拒绝

2）再连接存在的端口
[root@localhost ~]# telnet localhost 22
Trying ::1...
Connected to localhost. #看到Connected就连接成功了
Escape character is '^]'.
SSH-2.0-OpenSSH_5.3
a
Protocol mismatch.
Connection closed by foreign host.

2、使用ssh判断
ssh是linux的标准配置并且最常用，可以用来判断端口吗？
用法: ssh -v -p port username@ip
-v 调试模式(会打印日志).
-p 指定端口
username可以随意
1）连接不存在端口
[root@localhost ~]# ssh 10.0.250.3 -p 80
ssh: connect to host 10.0.250.3 port 80: Connection refused
[root@localhost ~]# ssh 10.0.250.3 -p 80 -v
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 10.0.250.3 [10.0.250.3] port 80.
debug1: connect to address 10.0.250.3 port 80: Connection refused
ssh: connect to host 10.0.250.3 port 80: Connection refused

2）连接存在的端口
[root@localhost ~]# ssh ... -p 
a
^]
^C
[root@localhost ~]# ssh ... -p -v
OpenSSH_.p, OpenSSL ..e-fips Feb 
debug: Reading configuration data /etc/ssh/ssh_config
debug: Applying options for *
debug: Connecting to ... [...] port .
debug: Connection established.
debug: permanently_set_uid: /
debug: identity file /root/.ssh/identity type -
debug: identity file /root/.ssh/identity-cert type -
debug: identity file /root/.ssh/id_rsa type -
debug: identity file /root/.ssh/id_rsa-cert type -
debug: identity file /root/.ssh/id_dsa type -
debug: identity file /root/.ssh/id_dsa-cert type -
a
^C

不用-v选项也可以咯
3、使用wget判断
wget是linux下的下载工具，需要先安装.
用法: wget ip:port
1）连接不存在的端口
[root@localhost ~]# wget ...:
---- ::-- http://.../
Connecting to ...:... failed: Connection refused.

2）连接存在的端口
[root@localhost ~]# wget ...:
---- ::-- http://...:/
Connecting to ...:... connected.
HTTP request sent, awaiting response...