Two methods for modifying ssh ports in linux

This article mainly introduces two methods for modifying the ssh port in linux. For more information, see

Smoothly modify the sshd port in linux

First:

1. if you want to change the SSH default port (22), you only need to modify it:

Copy codeThe code is as follows:
Port 22 in/etc/ssh/sshd_config

Change 22 to the port you want to set here, but do not set the same as the existing port to avoid unknown consequences.

2. if you want to restrict the SSH login IP address, you can do the following:

First: modify/etc/hosts. deny and add

Copy codeThe code is as follows:
Sshd: ALL

Then, modify:/etc/hosts. allow and set it as follows:

Copy codeThe code is as follows:
Sshd: 192.168.0.241

In this way, only the IP address 192.168.0.241 can be bound to log on to the LINUX machine through SSH. Of course, as a server, I do not install gnome or KDE, and many things do not, which increases the security factor.

Second: (strongly recommended)

First, modify the configuration file.

Copy codeThe code is as follows:
Vi/etc/ssh/sshd_config

Find the section # Port 22, which indicates that Port 22 is used by default and changed to the following:

Copy codeThe code is as follows:
Port 22
Port 50000

Save and exit

Run

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/Etc/init. d/sshd restart

In this way, the SSH Port will work on both 22 and 50000.

Now edit the firewall configuration:

Copy codeThe code is as follows:
Vi/etc/sysconfig/iptables

Port 50000 is enabled.

Run

Copy codeThe code is as follows:
/Etc/init. d/iptables restart

Now, use the ssh tool to connect to Port 50000 to test whether the connection is successful. If the connection is successful, edit the settings of sshd_config again and delete Port22.
The reason for setting two ports first and then disabling one after the test is successful is to prevent unknown situations such as disconnection, network disconnection, and misoperation during the conf modification process, you can also connect to the debugging through another port to avoid the need to send people to the data center if the connection fails, making the problem more complicated and troublesome.