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如何测试服务器端口通不通

经常会遇到测试服务器端口通不通的情况,在window上常用的是Telnet,不过Linux下Telnet是需要安装的.



一般情况下使用"telnet ip port"判断端口通不通,其实不止这一种,还有很多种方法:

准备环境

启动一个web服务器,提供端口.


[it.net.cn@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

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

1
2
3
[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...



4、使用端口扫描工具


[root@localhost ~]# nmap ... -p
Starting Nmap . ( http://nmap.org ) at -- : CST
Nmap scan report for ...
Host is up (.s latency).
PORT STATE SERVICE
/tcp closed http
MAC Address: B:A::CF:FD:D (Unknown)
Nmap done: IP address ( host up) scanned in . seconds
[root@localhost ~]# nmap ... -p
Starting Nmap . ( http://nmap.org ) at -- : CST
Nmap scan report for ...
Host is up (.s latency).
PORT STATE SERVICE
/tcp open http-proxy
MAC Address: B:A::CF:FD:D (Unknown)
Nmap done: IP address ( host up) scanned in . seconds
[root@localhost ~]# nmap ...
Starting Nmap . ( http://nmap.org ) at -- : CST
Nmap scan report for ...
Host is up (.s latency).
Not shown: closed ports
PORT STATE SERVICE
/tcp open ssh
/tcp open rpcbind
/tcp open http-proxy
/tcp open unknown
MAC Address: B:A::CF:FD:D (Unknown)
Nmap done: IP address ( host up) scanned in . seconds
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.

一般在windows下使用telnet比较方便,linux 下wget  ssh 比较方便些.


(责任编辑:IT)