Example of modifying SSH port number in CentOS

1, with putty or other terminals to connect the CentOS system, Vi/etc/ssh/sshd_config, find #port 22

2, remove the #port 22 before the #, and then put the copy to the following, such as the 22nd port to 2020, modified as follows:

Port 22

Port 2020

Save exit

3, in the terminal input service sshd restart return, restart SSH

4, inside the firewall to open 2020 this port number, in the terminal input Vi/etc/sysconfig/iptables carriage return:

Add a row:-a rh-firewall-1-input-p tcp-m state-m tcp--dport 2020--state new-j ACCEPT

Save exit

5, in the terminal input service iptables Restart carriage return, restart the firewall

6, in putty or other terminals with a new port connection CentOS, the correct connection to indicate the configuration is correct, you can enter/etc/ssh/sshd_config file to remove port 22 ports