Shulou(Shulou.com)06/03 Report--

Today, what the editor shares with you is the introduction of the method of closing and opening the linux port, which is not well understood by many people. Today, in order to let you know more about the method of closing and opening the linux port, I have summarized the following contents for you. Let's look down together. I'm sure you'll get something.

First, check which ports are open

Netstat-anp

(note: adding the parameter'- n 'will convert the application to port display, that is, addresses in numeric format, such as: nfs- > 2049, ftp- > 21, so you can open two terminals, one by one corresponding to the port number of the program)

2. Turn off the port number

Iptables-An OUTPUT-p tcp-- dport port number-j DROP

Third, hit the slogan of the beginning:

Iptables-An INPUT-ptcp-- dport port number-j ACCEPT

Save settings

Service iptables save

5. The following is how to use the linux open port command.

Nc-lp 23 & (Open port 23, that is, telnet) netstat-an | grep 23 (check whether port 23 is open)

6. Linux Open Port Command every open port requires a corresponding listener

The above is a brief introduction to the method of closing and opening the linux port. Of course, the differences in the detailed use of the above have to be understood by everyone. If you want to know more, welcome to follow the industry information channel!

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