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
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(curl同理)
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...