判断端口通不通的几种方法
妙音
posted @ 2014年8月22日 21:05
in linux
with tags
端口;windows;linux
, 22366 阅读
通常使用"telnet ip port"判断端口通不通. 有其它方法吗？先看下面的几种方法
准备环境
启动一个web服务器，提供端口.
[wyq@localhost ~]$ python -m SimpleHTTPServer 8080 Serving HTTP on 0.0.0.0 port 8080 ...
用其它web服务器提供端口也一样，由于python比较方便，这里就用它
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
先用telnet连接不存在的端口
[wyq@localhost ~]$ telnet localhost 9000 Trying 127.0.0.1... telnet: connect to address 127.0.0.1: Connection refused
直接提示连接被拒绝
再连接上面提供的端口
[wyq@localhost ~]$ telnet localhost 8080 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'.
看到"Connected to localhost." 可以知道连接成功了.
后台服务器有什么反映？
[wyq@localhost monitor]$ python -m SimpleHTTPServer 8080 Serving HTTP on 0.0.0.0 port 8080 ...
没有任何反映
此时telnet停住了，随便输入一个字符"a"，然后回车
[wyq@localhost ~]$ telnet localhost 8080
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
a
<head>
<title>Error response</title>
</head>
<body>
<h1>Error response</h1>
<p>Error code 400.
<p>Message: Bad request syntax ('a').
<p>Error code explanation: 400 = Bad request syntax or unsupported method.
</body>
Connection closed by foreign host.
再看服务器
[wyq@localhost monitor]$ python -m SimpleHTTPServer 8080
Serving HTTP on 0.0.0.0 port 8080 ...
127.0.0.1 - - [22/Aug/2014 07:15:16] code 400, message Bad request syntax ('a')
127.0.0.1 - - [22/Aug/2014 07:15:16] "a" 400 -
上面是linux环境下telnet连接一个web服务端口的情况.
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
usernmae可以随意
连接不存在端口
[wyq@localhost ~]$ ssh -v -p 9000 wyq@localhost OpenSSH_6.4, OpenSSL 1.0.1e-fips 11 Feb 2013 debug1: Reading configuration data /home/wyq/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 51: Applying options for * debug1: Connecting to localhost [127.0.0.1] port 9000. debug1: connect to address 127.0.0.1 port 9000: Connection refused ssh: connect to host localhost port 9000: Connection refused
"Connection refused"表示端口不可用
连接存在的端口
[wyq@localhost ~]$ ssh -v -p 8080 wyq@localhost
OpenSSH_6.4, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /home/wyq/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 51: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 8080.
debug1: Connection established.
debug1: identity file /home/wyq/.ssh/id_rsa type 1
debug1: identity file /home/wyq/.ssh/id_rsa-cert type -1
debug1: identity file /home/wyq/.ssh/id_dsa type -1
debug1: identity file /home/wyq/.ssh/id_dsa-cert type -1
debug1: identity file /home/wyq/.ssh/id_ecdsa type -1
debug1: identity file /home/wyq/.ssh/id_ecdsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.4
debug1: ssh_exchange_identification: <head>
debug1: ssh_exchange_identification: <title>Error response</title>
debug1: ssh_exchange_identification: </head>
debug1: ssh_exchange_identification: <body>
debug1: ssh_exchange_identification: <h1>Error response</h1>
debug1: ssh_exchange_identification: <p>Error code 400.
debug1: ssh_exchange_identification: <p>Message: Bad request syntax ('SSH-2.0-OpenSSH_6.4').
debug1: ssh_exchange_identification: <p>Error code explanation: 400 = Bad request syntax or unsupported method.
debug1: ssh_exchange_identification: </body>
ssh_exchange_identification: Connection closed by remote host
"Connection established" 表示已经连上端口
服务器输出
[wyq@localhost ~]$ python -m SimpleHTTPServer 8080
Serving HTTP on 0.0.0.0 port 8080 ...
127.0.0.1 - - [22/Aug/2014 13:32:55] code 400, message Bad request syntax ('SSH-2.0-OpenSSH_6.4')
127.0.0.1 - - [22/Aug/2014 13:32:55] "SSH-2.0-OpenSSH_6.4" 400 -
使用wget判断
wget是linux下的下载工具，需要先安装.
用法: wget ip:port
连接不存在的端口
[wyq@localhost ~]$ wget localhost:9000 --2014-08-22 13:36:42-- http://localhost:9000/ 正在解析主机 localhost (localhost)... 127.0.0.1 正在连接 localhost (localhost)|127.0.0.1|:9000... 失败：拒绝连接。
连接存在的端口
[wyq@localhost ~]$ wget localhost:8080 --2014-08-22 13:37:22-- http://localhost:8080/ 正在解析主机 localhost (localhost)... 127.0.0.1 正在连接 localhost (localhost)|127.0.0.1|:8080... 已连接。 已发出 HTTP 请求，正在等待回应... 200 OK 长度：2770 (2.7K) [text/html] 正在保存至: “index.html” 100%[======================================>] 2,770 --.-K/s 用时 0s 2014-08-22 13:37:22 (105 MB/s) - 已保存 “index.html” [2770/2770])
总结
提供端口服务，则使用了tcp协议，上面是以web服务器为例。如果服务器是更简单的tcp服务器，三个工具同样适用.
三个工具的共同点是：1.以tcp协议为基础；2.能访问指定端口. 遵循这两点可以找到很多工具.
在windows下使用telnet比较方便，linux下个人就比较喜欢用wget.
2023年8月03日 06:51
Very nice article, I enjoyed reading your post, very nice share, I want to twit this to my followers. Thanks. It is very difficult to find a good Shia Quran Center with Shia teachers abroad except in Muslim or especially Shia majority countries. Fortunately, Imamia Quran Academy has realized this need and has launched the Shia Online Quran Center. Join our Online Shia Quran Academy now, and Start your free 3 days Trial.